WO2008026333A1 - High-strength flame resistant magnesium alloy - Google Patents

Abstract

A high-strength flame resistant magnesium alloy produced by adding, as a supplement additive, at least one member selected from among carbon (C), molybdenum (Mo), niobium (Nb), silicon (Si), tungsten (W), alumina (Al2O3), magnesium silicide (Mg2Si) and silicon carbide (SiC) to a small-piece block of flame resistant magnesium alloy resulting from addition of 0.5 to 5.0 mass% of calcium to a magnesium alloy, and subjecting the resultant matter to crushing, molding, sintering and plastic working. As the high-strength flame resistant magnesium alloy excels in joining capability, when it is applied to a filler metal, there can be attained an enhancement of weldability.

Description

 Specification

 High strength flame retardant magnesium alloy

 Technical field

 [0001] The present invention relates to a high-strength flame-retardant magnesium alloy in which the mechanical strength of the flame-retardant magnesium alloy is increased.

 Background art

 [0002] Magnesium alloys are attracting attention as substitutes for aluminum and its alloys because they are extremely lightweight. Magnesium alloys are the lightest of all practical metals, and have a relatively high specific strength, specific elastic modulus, etc., obtained by dividing strength and elastic modulus by density. For this reason, demand is expected to increase in the future in the industrial field where weight reduction is required. Although titanium and aluminum alloys have sufficient strength, they have disadvantages such as low weight and buffering properties compared to magnesium alloys.

 [0003] Although conventional magnesium alloys have a relatively high specific strength, they are known to have a disadvantage that they are easy to ignite due to their lower absolute strength and lower ignition point than titanium and aluminum alloys. Yes. For this reason, in order to make it flame-retardant, a flame retardant magnesium alloy made by adding strength to the magnesium alloy to raise its ignition point and make it difficult to ignite, was subjected to plastic casing such as extrusion and rolling. Flame retardant magnesium alloys have been developed (Patent Document 1).

 [0004] Various magnesium alloys that have been improved to obtain the strength corresponding to titanium and aluminum alloys have been proposed. For example, Mg has Ca, Zn, and X (where X is a rare earth element, Y, Ce, La, Nd, A magnesium alloy having a microstructure in which a predetermined amount of one or more elements selected from the group force consisting of Pr, Sm, and Mm is added and a finely dispersed structure of these compounds is disclosed (for example, patents) Reference 2). That is, a predetermined amount of rare earth element is added and the structure is refined by rapid solidification atomization.

[0005] In addition, as one that realizes high strength and high ductility at the same time, it is one kind of solute atom that is included in the periodic table group 2, group 3, or lanthanoid system and has a larger atomic radius than magnesium. 0.5 A magnesium alloy composed of 4 atomic% and the balance of magnesium is disclosed (for example, see Patent Document 3). This magnesium alloy has an average grain size of 1.5 μΐη or less, and solute atoms in the vicinity of the grain boundary are unevenly distributed at a concentration 1.5 to 10.0 times the concentration of the solute atoms in the grain. It has a fine crystal grain structure.

[0006] Further, as a magnesium alloy having both high strength and high ductility, 1.0 to 4.0 atomic% of Zn and 1.0 to 4.5 atomic% of Y are added to magnesium at a predetermined composition ratio. The structure that contains the intermetallic compound Mg Y Zn and the long-period structure Mg YZn at the same time is opened.

 3 2 12

 (For example, see Patent Document 4). This is because the intermetallic compound Mg Y Zn and the long period

 3 2

 Phase Mg YZn coexists to improve resistance to strength, tensile strength and elongation

12

 It is.

 [0007] Further, as described above, a flame-retardant magnesium alloy containing calcium in a magnesium alloy has a high ignition point, a high mechanical strength, and an easy-to-handle characteristic. For this reason, a technology that uses this advantage to apply this magnesium alloy to a helmet as a product (for example, see Patent Document 5) and a technology that applies to a frame of glasses (for example, see Patent Document 6) are also disclosed. ing. Magnesium alloys, on the other hand, are expected to be widely applied to structural members such as moving structures such as automobiles, motorcycles, railway vehicles, airplanes, robots, welfare equipment, and elderly equipment.

 [0008] In such various structural members, joining of each member, particularly welding technology is indispensable. Various developments have also been made in the welding technology for magnesium alloys, including laser welding, TIG welding, MIG welding, and so on. Although it is not a flame retardant magnesium alloy according to the present invention, for example, a magnesium weld wire that is excellent in surface cleanliness by applying a shaving process to the surface of a base material such as a magnesium-based alloy extruded material and then shaving the surface. It is disclosed (for example, see Patent Document 7). Also, this is not a flame retardant magnesium alloy according to the present invention, but a magnesium-based alloy wire excellent in strength and toughness containing components such as Al, Mn, Zn, Zr, and rare earth elements is known. (For example, see Patent Document 8).

[0009] Further, as described above, a flame retardant magnesium alloy in which calcium is contained in a magnesium alloy has a high ignition point, a high mechanical strength, and an easy-to-handle characteristic. This interest As a concrete example using the point, in the above-mentioned Patent Documents 5 and 6, in which the divided members are butted together, they are joined by fusion welding such as laser welding, TIG welding, MIG welding, etc. Technology is disclosed.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-109963

 Patent Document 2: Japanese Patent Laid-Open No. 9-41065

 Patent Document 3: Japanese Unexamined Patent Publication No. 2006-16658

 Patent Document 4: Japanese Unexamined Patent Publication No. 2006-97037

 Patent Document 5: Japanese Unexamined Patent Publication No. 2005-350808

 Patent Document 6: Japanese Unexamined Patent Publication No. 2005-196094

 Patent Document 7: Japanese Unexamined Patent Publication No. 2006-263744

 Patent Document 8: Japanese Patent No. 3592310

 Disclosure of the invention

 Problems to be solved by the invention

 [0011] As described above, various improved techniques for improving the mechanical properties of magnesium alloys have been proposed. However, the current magnesium alloys still have many problems, are not satisfactory, and are still insufficient to be applied to actual products. The technology of Patent Document 1 is the application of the present applicant, but the high-strength flame-retardant magnesium alloy contains 0.1 to 15% by mass of Ca, and is partially added with Al and Zn. It is. The present invention is an alloy which is developed from this technology and further strengthened. Patent Document 2 requires the addition of expensive rare earth elements, and the resulting alloy must be expensive. Furthermore, special and advanced techniques such as rapid solidification atomization must be used. Although the strength of the alloy according to Patent Document 2 is 510 to 635 MPa and high strength is achieved, the elongation at break is extremely small, 1.0 to 4.0%, and it is a very brittle and tenuous material. ing.

[0012] Although the technique of Patent Document 3 is exemplified as an improvement in yield stress and elongation, the other elements excluding Ca of the designated solute atom are rare earth elements, so that Similarly, it becomes an expensive alloy. Furthermore, in the magnesium alloy described in Patent Document 4, the intermetallic compound Mg Y Zn and the long-period phase Mg YZn are present simultaneously. Only, a tensile strength of 390 to 520 MPa and a elongation of 4.5 to 10.3% can be obtained. It is shown that you can't have both.

 [0013] Further, the technique of Patent Document 7 is intended to improve the surface cleanliness of the force weld line, which is related to the magnesium weld line. The composition of the so-called filler material such as the weld line and the weld rod It ’s not about anything. This is not a flame retardant magnesium alloy. Furthermore, the technique of Patent Document 8 includes components such as Al, Mn, Zn, Zr, rare earth elements, etc., which disclose techniques related to magnesium-based alloy wires. The composition is different from that of the heat-resistant magnesium alloy filler material. The content of Patent Document 8 is intended to provide a spring using a wire, and its use as a weld line is disclosed, but no specific example is described. Furthermore, this weld line does not relate to a flame retardant magnesium alloy.

 [0014] Further, in Patent Document 5, a flame retardant magnesium alloy is applied to helmet and, if necessary, the magnesium alloy is melt welded such as laser welding, TIG welding, MIG welding, etc. The possibility of welding is disclosed. However, there is no description of specific examples. Further, what is described in Patent Document 5 is that the flame retardant magnesium alloy is a material to be welded on the side to be welded, and is not a filler material for welding.

 [0015] As described above, the magnesium alloys described in Patent Documents 2, 3, and 4 have advantages, but are insufficient as properties required for machine materials, and are added in any case. An expensive rare earth element is used as an element, and the resulting magnesium alloy has a problem of becoming expensive. In Patent Documents 5 and 6, although the joining technique is disclosed, the target flame-retardant magnesium alloy is not the high-strength flame-retardant magnesium alloy according to the present invention. Furthermore, the techniques described in Patent Documents 7 and 8 are related to the improvement of the surface properties of the weld line, the use of expensive rare earth elements, and the improvement of the mechanical properties of the wire itself. , Les and misalignments are not high strength flame retardant magnesium alloys according to the present invention and their characteristics are insufficient.

[0016] The present invention has been made based on such a conventional technical background, and achieves the following object. The object of the present invention is to use a flame retardant magnesium alloy that does not use an alloying element limited to rare earth elements, and has high strength characteristics such as high tensile strength and high strength by adding general-purpose elements and compounds. Is in the provision of.

 Another object of the present invention is to provide a flame-retardant magnesium alloy that can be stably used at low cost and can be used as a filler material.

 Means for solving the problem

 The present invention takes the following means in order to achieve the above object.

 The high-strength flame-retardant magnesium alloy of the present invention 1 is obtained by adding carbon (C), molybdenum (Mo), niobium to a flame-retardant magnesium alloy in which 0.5 to 5.0 mass% of calcium is added to the magnesium alloy. (Nb), Silicon (Si), Tungsten (W), Anolemina (Al 2 O 3), Magnesium silicide

 twenty three

 At least one additional additive selected from shim (Mg Si) and silicon carbide (SiC)

 2

 It is obtained by adding the product.

 [0018] The high-strength flame-retardant magnesium alloy of the present invention 2 is characterized in that, in the present invention 1, the amount of the additional additive carbon (C) is from 0.:! To 0.3% by mass. To do.

High-strength flame retardant magnesium alloy of the present invention 3, in the present invention 1, the amount of additional additive Caro product molybdenum (Mo) is characterized in that 1. 0 12. 0 mass ^_0/0.

[0019] The high-strength flame-retardant magnesium alloy of the present invention 4 is characterized in that, in the present invention 1, the amount of the additional additive niobium (Nb) is 0.5 to 5.0% by mass. .

 The high-strength flame-retardant magnesium alloy of the present invention 5 is characterized in that, in the present invention 1, the amount of the additional additive silicon (Si) is 0.5 to 6.0 mass%.

[0020] High strength flame retardant magnesium alloy of the present invention 6, in the present invention 1, the amount of the additional additive Caro was tungsten (W) is characterized by 5. 0-40. 0 mass _^0/0 And

 The high strength flame-retardant magnesium alloy of the present invention 7 is characterized in that, in the present invention 1, the amount of the additional additive alumina (Al 2 O 3) is 1.0 to 5.0% by mass.

 twenty three

 [0021] The high-strength flame-retardant magnesium alloy of the present invention 8 is characterized in that, in the present invention 1, the amount of the additional additive magnesium silicide (Mg Si) is 2.0 to 60 mass%. And

 2

The high-strength flame-retardant magnesium alloy of the present invention 9 is characterized in that, in the present invention 1, the amount of the additional additive silicon carbide (SiC) is 0.7 to 20.0 mass%. [0022] High strength flame retardant magnesium alloy of the present invention 10, in the present invention 1, wherein the magnesium © beam alloys, 0:. 12.0 mass _^0/0 of Anoreminiumu 0-5 0 weight _^0/0 characterized in that it is a zinc and 0.5 mass _^0/0 following magnesium alloy containing manganese.

 The high-strength flame-retardant magnesium alloy of the present invention 11 is based on the present invention 1, and the magnesium alloy is an AZ31, AZ61, or AZ80 system defined by the American Society for Testing and Materials (ASTM).

A magnesium alloy selected from the group consisting of AZ91, AZ92, AM50, AM60, and AM100.

[0023] The high-strength flame-retardant magnesium alloy of the present invention 12 is characterized in that, in the present invention 1, the flame-retardant magnesium alloy is a flame-retardant magnesium alloy comprising a pulverized product obtained from the alloy material. And

 The high-strength flame-retardant magnesium alloy of the present invention 13 is characterized in that, in the present invention 1, the high-strength flame-retardant magnesium alloy is an alloy manufactured by plastic working after adding the additional additive. To do.

[0024] The high-strength flame-retardant magnesium alloy of the present invention 14 is the high-strength flame-retardant magnesium according to the present invention 12, wherein the powdered material is a cutting waste obtained by cutting or a powdered body thereof. alloy.

 The high-strength flame-retardant magnesium alloy of the present invention 15 is the same as the thirteenth aspect of the present invention, wherein the plastic calendering is selected from extrusion processing, drawing processing, rotary forging processing and rolling processing.

Or a combination of two or more types.

[0025] The high-strength flame-retardant magnesium alloy of the present invention 16 is characterized in that, in the present inventions 1 to 15, the alloy constituted by addition of the additional additive is an alloy constituting the filler material. Let's say.

 The high-strength flame-retardant magnesium alloy of the present invention 17 is characterized in that, in the present invention 16, the filler material is a linear or rod-shaped welding material.

 The invention's effect

[0026] As described above, the high-strength flame-retardant magnesium alloy of the present invention does not use an alloying element limited to expensive rare earth elements, and is based on the addition of general-purpose elements and compounds. In addition, the tensile strength is increased by forming, sintering and plastic working of the powdered material. It became a low-cost flame-retardant magnesium alloy with high strength and high strength. Furthermore, as a filler material, the addition of Ca has a high ignition point and can be joined in a normal state, and fumes generated during welding work (substances evaporated by heat during welding or cutting are cooled to form solid particulates. It became a high-strength flame-retardant magnesium alloy. Furthermore, by effectively using pulverized materials such as cutting waste, a high-strength flame-retardant magnesium alloy with improved bondability at low cost was obtained.

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0027] [High-strength flame-retardant magnesium alloy]

 Hereinafter, embodiments of the flame-retardant magnesium alloy of the present invention will be described in detail. First, in order to facilitate understanding of the present invention, a magnesium alloy will be described. Magnesium alloys are standardized by the American Society for Testing Materials (hereinafter referred to as “ASTM”) or the Japanese Industrial Standards (hereinafter referred to as “JIS”). Magnesium alloys are roughly classified into forging magnesium alloys and wrought magnesium alloys. For each, the range from the minimum value to the maximum value of the mechanical properties standardized by ASTM and JIS is as follows. The composition of the chemical components of these standardized alloys has been standardized and is a well-known technique, so detailed description thereof will be omitted.

 [0028] The mechanical properties of the magnesium alloy for forging are as follows. Tensile strength: 140MPa (AM100A—F #) ~ 270MPa (ZK61A—T5, T6 treated material). Resistance: 70MPa (AM10 OA—F material) to 180MPa (ZK61A—T5, Τ6 treated material). Elongation: Almost 0% (AM100A—F material) to 10% (ΑΜ50Α—F material).

 [0029] The mechanical properties of the wrought magnesium alloy are as follows. Tensile strength: 190MPa (8∑3100_0 material) to 310MPa (ZK60A—T5 treated material). Resistance: 90MPa (AZ31C_〇 material) to 230MPa! Elongation: 4. /. (AZ31 C HI 4 treated material) ~ 13% ^ 31〇_0 material).

[0030] In general, in the case of metals, the mechanical properties such as strength and ductility are significantly improved in the wrought alloy as compared with the forging alloy due to the effects of plastic working and heat treatment. Although the magnesium alloy has improved as described above, the strength and ductility are currently less than those of other metals. For this reason, further technical development has been conducted and The technology is disclosed as in the case of licensed technology.

 [0031] In the present embodiment, a low-price element or compound additive is added to a flame retardant magnesium alloy that has been made flame retardant by adding Ca to improve its mechanical strength. It is. This embodiment uses a pulverized product of a flame retardant magnesium alloy, and is formed, sintered, and plastically processed. A flammable magnesium alloy is proposed.

 [0032] Next, the alloy will be described. The magnesium alloy shown in the embodiment of the present invention is a magnesium alloy for fabrication represented by ASTM [AM60B]. However, the alloy capable of carrying out the present invention is not necessarily limited to this magnesium alloy for forging [AM60B], but may be other magnesium alloys. 0.5 to 5.0% by mass of Ca is added to this alloy. In the present embodiment, 2 mass% of Ca is added.

[0033] AM60B is an alloy for die casting, and is a high-purity magnesium alloy in which the contents of impurities Fe, Ni, and Cu are reduced in order to improve corrosion resistance. Its basic chemical composition A. 5 to 6. 5 mass _^0/0, MnO. 24-0. 60 wt _^0/0, with the remainder being magnesium. The strength is added to make it a flame retardant magnesium alloy. The amount of calcium added is preferably 0.5 to 5.0% by mass as described above.

 [0034] Magnesium has a dense hexagonal crystal structure, so that cold working cannot be performed at room temperature because of its extremely poor plastic cacheability. Although hot plastic workability is significantly improved, it is still difficult to machine a precise shape compared to other metals. Therefore, the forging method is mainly used for the production of magnesium alloys. In addition, forging products obtained by the forging method, forging materials obtained by plastic working, wrought materials, etc., are often subjected to cutting to finish the final shape. However, the treatment of the cutting waste generated in the cutting process is limited in terms of cost and the like, and on the other hand, there are many problems in reusing it as a recycled material.

[0035] The force that has been researched to make effective use of this cutting waste in recent years has not yet been disclosed. In this example, it is based on cutting waste of a flame retardant magnesium alloy. Since this flame-retardant magnesium alloy has good machinability, high-speed cutting is possible, and therefore a large amount of cutting waste can be generated. But, In the present invention, the present invention is not limited to the cutting waste, and any crushed material or small block may be used as long as it conforms to the cutting waste.

 [0036] [Method for producing high-strength flame-retardant magnesium alloy]

 Next, the method for producing the high-strength flame-retardant magnesium alloy of the present invention will be described. As the base magnesium alloy, a flame retardant magnesium alloy “AM60B + 2Ca alloy” to which 2 mass% of Ca was added was used in the present embodiment. AM60B is a magnesium alloy that is inherently a forging, and enables plastic molding such as extrusion in the heat and heat. This plastic cage includes extrusion force, drawing, forging, rotary forging, and rolling. By adding 2 mass% Ca to this AM60B, the ignition temperature of the flame retardant magnesium alloy "AM60B + 2Ca alloy" with 2 mass% Ca added to this AM60B can be increased by 200-300 ° C. .

 [0037] For this reason, melting work in the atmosphere can be performed safely. From this flame retardant magnesium alloy “AM60B + 2Ca alloy”, a small block having a form suitable for pulverization in the next process is obtained. In the present embodiment, the cutting waste produced by cutting the flame retardant magnesium alloy “AM60B + 2Ca alloy” was used for convenience. Needless to say, the small blocks are not limited to cutting scraps by cutting. Cutting scraps and grinding scraps discharged by various machining processes, press scraps such as cutting and punching, and shredding by breakers. Debris, porcelain · Small pieces of forged material, etc. may be finely ground. These small block-like forces Force to obtain the powdered material A ball mill or the like is used for this.

[0038] In the case of the flame retardant magnesium alloy according to the present embodiment, flame retardancy is achieved by the addition of Ca. Therefore, it is safe to leave the pulverized product in the atmosphere at room temperature. For example, the lower explosion limit value of the pulverized product of the flame retardant magnesium alloy “AM60B + 2Ca alloy” having an average particle size of 146 μm is 100 mg / m ³ , which is larger than aluminum powder (35 mg Zm ³ ). It is about powder (<120mgZm ³ ), and the risk of explosion is greatly reduced, making it easy to handle.

[0039] Next, when obtaining a pulverized product from the small block, a predetermined element or compound is added as an additional additive, which is a feature of the present embodiment. This additional additive is not limited to rare earth elements, and including its proportion, 0.:! To 0.3 mass% 〇, 1.0 to 12.0 mass ⁰ / ^oMo, 0. ^{5~5. 0} mass _{^{0/0 Nb, 0. 5~6.}} 0 mass _{^{0/0 Si, 5. 0~40.}} 0 wt% W, 1. 0 to 5 - 0 weight ⁰ / OAl_〇, from 2.0 to 6, 0 mass _^0/0 Mg Si, 0. 7 to 20, 0 wt _^0/0 Si

 2 3 2

 Each element of c, or these predetermined compounds.

 [0040] The reason for limiting the type and amount of these elements or compounds is the range in which the flame-retardant magnesium alloy produced can achieve high strength. This is because the effect of strengthening is weakened. Add one or more of these, and simultaneously pulverize small blocks and combine elements or compounds. In other words, in this pulverization process, the flame-retardant magnesium alloy in the small block form is reformed to a fine homogeneous structure by breaking the solidified structure. At the same time, the additive is uniformly introduced into the powder, and the flame-retardant magnesium alloy has a fine and homogeneous structure.

 [0041] [Molding and sintering]

 Next, the pulverized flame-retardant magnesium alloy having such a fine and homogeneous structure is formed and sintered. This forming can be either cold forming or hot forming. However, in consideration of shortening of the process, hot forming capable of simultaneous sintering is preferable. The pulse current sintering method is suitable for hot forming. The no-less current sintering method is a known processing method in which a target sample is filled in a graphite mold, and is sintered by applying a current in pulses while applying pressure. In this example, this sample is the above-mentioned flame retardant magnesium alloy powder. This treatment method has the advantage that the powdered material can be efficiently heated and sintered in a short time.

[0042] Next, the formed and sintered fire-retardant magnesium alloy pulverized sintered body is subjected to plastic working using a billet. This plastic working has an effect of making the sintered body more firmly fixed than the sintered body by imparting shear deformation to the sintered body, and also making the microstructure of the sintered body finer. Various plastic working methods such as extrusion, rolling, drawing, forging, and rotary forging are available as means for plastic working. In this example, a hot extrusion force that is performed at a temperature higher than the recrystallization temperature of the material is used. This is because extrusion shear can impart large shear deformation to the workpiece. In this case, the higher the extrusion ratio, the higher the mechanical strength of the obtained material. However, if it is increased more than necessary, the extrusion mold will have a reduced service life or damage, and the extrusion equipment will become larger. The maximum of about 120 is preferable. [0043] By this extrusion molding, the pulverized products in the sintered body are subjected to shear deformation and are more firmly bonded, so that the intermetallic compound particles originally contained in the flame-retardant magnesium alloy and the additional additive are magnesium matrix. The tissue form is uniformly dispersed therein. Also, recrystallization occurs during hot extrusion and the magnesium matrix crystal grains are refined. These improve the mechanical characteristics and increase the strength.

 [0044] The magnesium alloy used is not limited to that disclosed in the above-described embodiment, but 0 to: 12.0 mass% aluminum, 0 to 5.0 mass% zinc, and 0.5 mass% or less. Effective results are also possible with a magnesium alloy containing manganese. In addition, magnesium alloy is one of the powers that can be selected from AZ31, AZ61, AZ80, AZ91, AZ92, AM50, AM60, and AM100 as listed by the American Material Testing Association (ASTM) standard. You can still get valid results using.

 [0045] The present invention can also be applied to a filler material using a high-strength flame-retardant magnesium alloy having such properties as a raw material. The filler metal used during welding operations, ie, welding rods or welding lines (or “welding wires”), etc., is added 0.5 to 5% by mass of force (Ca) to the magnesium alloy. In addition, any of C, Mo, Nb, Si, W, AlO, Mg Si, SiC

 2 3 2

 This is a high-strength magnesium alloy according to the present invention, to which one or more kinds of these are additionally added, and an alloy having a high ignition point and increased strength.

 [0046] Along with the incombustibility, the risk of a fire associated with the occurrence of a spark or the like is reduced in joining, and the joining work can be performed safely. In general, it is known that during the welding operation, fumes are generated by cooling the evaporated material due to the heat during welding and become solid fine particles. By using the filler material according to the present invention, The occurrence can be suppressed. In this way, it can contribute to the improvement of the welding environment even at actual welding sites.

 [0047] The filler material is obtained, for example, by a processing form in which the drawing force is applied by a roller die or the like specialized for drawing. By applying these processes, the additional additive contained in the filler metal of the present invention can be more uniformly dispersed in the magnesium matrix. The characteristics can be improved.

[0048] The high-strength flame-retardant magnesium alloy of the present invention has magnesium or magnesium as a filler material. When welding shim alloy materials, it can be applied to all types of welding regardless of the type of welding, but it can be used particularly favorably for TIG welding and MIG welding. An example of joining performed by TIG welding is also shown below. Although the embodiment has been described above, the present invention is not limited to the present embodiment, and it is not a problem.

 Example 1

 [0049] The alloy of this example was based on the flame retardant magnesium alloy “AM60B + 2Ca” to which 2.0% by mass ○ & was added in order to impart flame retardancy to the AM60B alloy. As additional additives, elements such as C, Mo, Nb, Si, W, AlO, Mg Si, SiC, or compounds are listed in Table 1.

 2 3 2

 It added so that it might become the composition shown in. In this embodiment, cutting scraps, which are turning chips, were used as small blocks of this alloy. The cutting waste was pulverized by a ball mill to obtain a pulverized product. At this time, an additional additive was also added at the same time, and the additive was uniformly dispersed and compounded.

 [0050] Next, the pulverized product of the flame-retardant magnesium alloy prepared by this ball mill was solidified and formed in the atmosphere at a sintering temperature of 480 ° C for 20 minutes by a pulse current sintering method. This was then used as a billet for hot extrusion at an extrusion ratio of 110 and an extrusion temperature of 480 ° C. Test pieces were collected in the longitudinal direction of the extruded material and tested for tensile strength, yield strength, and elongation at break at room temperature. The test results are summarized in Table 2. According to this result, the tensile strength was 419 MPa or more and the proof stress was 380 MPa or more in any of the test pieces, and the effect of the present invention was confirmed.

[0051] [Table 1]

Composition (wt%)

 Test material

AM60B +2 Ca C Mo Nb Si W Al ₂ 0 ₃ g ₂ Si SiC

 1 99.9 0.1

 2 99.8 0.2

 3 98.9 1.1

 4 94.5 5.5

 5 89.5 10.5

 6 99.0 1.0

 7 95.4 4.6

 8 99.0 1.0

 9 95.0 5.0

 10 94.8 5.2

 1 1 87.9 18.1

 12 63.7 36.3

 13 98.9 1.1

 14 95.6 4.4

 15 97.8 2.2

 16 94.5 5.5

 17 90.1 9.9

 18 98.2 1.8

 19 91.3 8.7

 20 83.4 16.6

[Table 2]

Figures 1 to 8 show the data for each element or compound. Fig. 1 shows the case where C is added, Fig. 2 shows the case where Mo is added, Fig. 3 shows the case where Nb is added, Fig. 4 shows the case where Si is added, Fig. 5 shows the case where W is added, and Fig. 6 shows the case where W is added. Figure 7 shows the addition of Mg Si when Al 2 O is added. Fig. 8 is a data diagram showing the tensile strength, resistance to resistance, and elongation at break according to the amount of addition when SiC is added.

 [0053] According to this result, as compared with the conventional Ca-added high-strength flame-retardant magnesium alloy shown in Patent Document 1 without any additional additive, in this example, as is clear from the data diagram, The mechanical strength is also improved when the miscible additive is added. For example, the tensile strength will be 419MPa or more when adding any additional additive. Therefore, it can be said that the high-strength flame-retardant magnesium alloy as a raw material is an alloy with further improved strength. In each figure, the value when the addition amount is 0% indicates the result of the comparative example shown below.

 Next, since a comparison corresponding to the present embodiment was performed, a comparative example will be shown. The result of this example is superior to any of the following comparative examples.

 (Comparative Example 1)

 This Comparative Example 1 was conducted on a conventional flame retardant magnesium alloy, without any additional additives related to the present invention. Cutting scraps from a forged material of flame retardant magnesium alloy “A M60B + 2Ca” with the same chemical composition as in the example were pulverized by a ball mill, and then pulsed under exactly the same conditions as in the example. This pulverized product was formed and sintered by the electric current sintering method. Using this as a billet under the same conditions as in the example, hot extrusion at an extrusion ratio R = 110 and extrusion temperature T = 480 ° C was performed, and the resulting extruded material was pulled at room temperature in the longitudinal direction. A strength test was performed. As a result of the tensile strength test, the tensile strength was 415 MPa, the proof stress was 364 MPa, and the elongation at break was 23%. These values are shown at the left end with the amount of each additive being 0% in FIGS.

[0055] (Comparative Example 2)

 This Comparative Example 2 was carried out using a conventional flame retardant magnesium alloy having no additional additive according to the present invention. A flame-retardant magnesium alloy “AM60B + 2Ca” with the same chemical composition as in the example was extruded under the same conditions as in the example with an extrusion ratio of R = 110 and an extrusion temperature of T = 480 ° C. Cage, and a tensile strength test was conducted at room temperature in the longitudinal direction of the extruded material. The result of the tensile strength test is

 Tensile strength = 305 MPa, resistance to strength = 242 MPa, elongation at break = 18%.

[0056] (Comparative Example 3) This Comparative Example 3 was carried out using a conventional flame retardant magnesium alloy having no additional additive according to the present invention. A flame-retardant magnesium alloy “AM60B + 2Ca” having the same chemical composition as in the examples was extruded with hot processing, and then with hot drawing, the drawn material was processed in the longitudinal direction. The tensile strength test was conducted in the direction at room temperature. The result of the tensile strength test is

 Tensile strength = 286 MPa, strength = 198 MPa, elongation at break = 16%.

 Example 2

 [0057] This example shows the joining results when the high-strength flame-retardant magnesium alloy shown in Figs. 1 to 8 is used as a welding wire as a filler metal for magnesium alloy welding. As the material to be welded, an extruded plate material (plate thickness 2 mm) of a flame retardant magnesium alloy “AM60B + 2Ca alloy” added with 2 mass% of Ca to impart flame retardancy to the AM60B magnesium alloy was used. Welding was performed by the TIG method. The main welding conditions are as follows.

 [0058] That is, a pure tungsten electrode with a diameter of 2.4 mm is used, the distance between the electrode and the base metal is 2 mm, the current is 100 A, the welding speed is 200 mm / min, and the inert gas is argon gas. The flow rate was 12L / min. After welding, the weld was removed to form a specimen, and a tensile strength test was performed to confirm the joint strength. The tensile strength test results are shown in Table 3, Fig. 9 and Fig. 10. Figure 9 shows the results for each additional additive element, and Figure 10 shows the results for each additional additive compound. The horizontal axes in Fig. 9 and Fig. 10 indicate the types of additional additives and their compositions. The results of the examples show that the additive 5Si and 9Mg Si

 Except 2, all of the results exceeded the comparative example, confirming the effect of the present invention. Note that the results for the additive 5Si and 9Mg Si are due to poor welding due to coarse weld defects.

 2

 This is not a regular strength test result.

[Table 3] Filler composition Tensile strength (MPa)

 0.1C 224

 0.2C 228

 1Mo 222

 6Mo 231

 11 o 222

 1Nb 241

 5Nb 231

 1Si 193

 5Si 59

 5W 191

 18W 196

 36W 176

1AI ₂ 0 ₃ 226

4AI ₂ 0 ₃ 188

2Mg ₂ Si 230

5Mg ₂ Si 199

9Mg ₂ Si 5

 2SiC 181

 9SiC 192

 17SiC 178

 Comparative Example 173

[0059] [Comparative Example 4]

 In this comparative example, the result of joining using a conventional flame retardant magnesium alloy without additional additives related to the present invention as a filler material is shown. As a filler material, that is, in this comparative example, as a welding wire, a flame retardant magnesium alloy “AM60B + 2Ca alloy” is made of a forging material, a hot extrusion force, and then a hot drawing. Extruded material was used. TIG welding was performed in the same manner as in the working examples and welding conditions. In the same manner as in the Examples, after welding, the excess portion in the welding was removed to obtain a test piece shape, and then a tensile strength test was performed to confirm the bonding strength. The results are shown in “Comparative Example” in Table 3 and “Comparative Example” in FIG. 9 and FIG. The joint tensile strength of the welded plate material in the comparative example was 173 MPa, which was smaller than in any of the examples.

 Brief Description of Drawings

 [0060] FIG. 1 is a data diagram of a tensile strength test result of a high-strength flame-retardant magnesium alloy when C is added to a pulverized product of the flame-retardant magnesium alloy “AM60B + 2Ca”.

[FIG. 2] FIG. 2 is a data diagram of a tensile strength test result of a high-strength flame-retardant magnesium alloy when Mo is added to a pulverized product of the flame-retardant magnesium alloy “AM60B + 2Ca”. [FIG. 3] FIG. 3 is a data diagram of the tensile strength test results of a high-strength flame-retardant magnesium alloy when Nb is added to the pulverized product of the flame-retardant magnesium alloy “AM60B + 2Ca”.

 [FIG. 4] FIG. 4 is a data diagram of a tensile strength test result of a high-strength flame-retardant magnesium alloy when Si is added to the powder of the flame-retardant magnesium alloy “AM60B + 2Ca”.

 FIG. 5 is a data diagram of a tensile strength test result of a high-strength flame-retardant magnesium alloy when W is added to a pulverized product of the flame-retardant magnesium alloy “AM60B + 2Ca”.

 [Figure 6] Figure 6 shows the addition of Al 2 O to the pulverized product of flame retardant magnesium alloy “AM60B + 2Ca”.

 FIG. 2 is a data diagram of tensile strength test results of a high-strength flame-retardant magnesium alloy in the case of 2 3.

[Figure 7] Figure 7 shows the addition of Mg Si to the pulverized product of flame retardant magnesium alloy “AM60B + 2Ca”.

 2 is a data diagram of tensile strength test results of a high-strength flame-retardant magnesium alloy in the case of 2;

[FIG. 8] FIG. 8 is a data diagram of a tensile strength test result of a high-strength flame-retardant magnesium alloy when SiC is added to a pulverized product of the flame-retardant magnesium alloy “AM60B + 2Ca”. 9] Fig. 9 is a data diagram including a comparative example showing the tensile strength test results of a welded plate material welded using a high-strength flame-retardant magnesium alloy containing additional additive elements as a filler metal.

 [FIG. 10] FIG. 10 is a data diagram showing a tensile strength test result of a welded plate material welded using a high-strength flame-retardant magnesium alloy containing an additive compound as a filler material, and includes a comparative example. .

Claims

The scope of the claims  [1] Flame retardant magnesium alloy in which 0.5 to 5.0% by mass of calcium is added to magnesium alloy, carbon (C), molybdenum (Mo), niobium (Nb), silicon (Si), Select from tungsten (W), alumina (A10), magnesium silicide (Mg Si), and silicon carbide (SiC)  2 3 2  A high-strength flame retardant magnesium alloy obtained by adding at least one additional additive.  [2] In the high-strength flame-retardant magnesium alloy according to claim 1,  A high-strength flame-retardant magnesium alloy characterized in that the amount of carbon (C) in the additional additive is from 0.:! To 0.3% by mass. [3] In the high-strength flame-retardant magnesium alloy according to claim 1,  A high-strength flame-retardant magnesium alloy characterized in that the amount of molybdenum (Mo) as the additional additive is 1.0 to 12.0% by mass. [4] In the high-strength flame-retardant magnesium alloy according to claim 1,  The amount of niobium (Nb) as the additional additive is 0.5-5% by mass, a high-strength flame-retardant magnesium alloy. [5] In the high-strength flame-retardant magnesium alloy according to claim 1,  The amount of silicon (Si) as the additional additive is 0.5 to 6.0 mass%, a high-strength flame-retardant magnesium alloy. [6] In the high-strength flame-retardant magnesium alloy according to claim 1,  A high-strength flame-retardant magnesium alloy characterized in that the amount of tungsten (W) as the additive is 5.0 to 40.0% by mass. [7] In the high-strength flame-retardant magnesium alloy according to claim 1,  The amount of the additional additive alumina (Al 2 O 3) is 1.0 to 5.0% by mass.  twenty three  High strength flame retardant magnesium alloy. [8] In the high-strength flame-retardant magnesium alloy according to claim 1,  The amount of the additive additive magnesium silicide (Mg Si) is 2.0 to 6.0 mass%.  2  High strength flame retardant magnesium alloy. [9] In the high-strength flame-retardant magnesium alloy according to claim 1, A high-strength flame-retardant magnesium alloy characterized in that the amount of the additional additive silicon carbide (SiC) is 0.7 to 20.0 mass%. [10] In the high-strength flame-retardant magnesium alloy according to claim 1, The magnesium alloy is 0: High, characterized in that 12. 0 mass _^0/0 of Anoreminiumu 0-5 0 weight _^0/0 Zinc and 0.5 mass% of magnesium alloy containing manganese. Strength Flame retardant magnesium alloy. [11] In the high-strength flame-retardant magnesium alloy according to claim 1,  The magnesium alloy is one type of magnesium alloy selected by AZ31, AZ61, AZ80, AZ91, AZ92, AM50, AM60 and AM100 as defined by the American Society for Testing Materials A high-strength flame-retardant magnesium alloy characterized by  [12] In the high-strength flame-retardant magnesium alloy according to claim 1,  The flame-retardant magnesium alloy is a high-strength flame-retardant magnesium alloy characterized by comprising a pulverized material obtained from the flame-retardant magnesium alloy material strength. [13] In the high-strength flame-retardant magnesium alloy according to claim 1,  The high-strength flame-retardant magnesium alloy is a high-strength flame-retardant magnesium alloy that is manufactured by plastic working that causes permanent deformation by applying an external force after adding the additional additive. [14] In the high-strength flame-retardant magnesium alloy according to claim 12,  A high-strength flame-retardant magnesium alloy characterized in that the pulverized material is cutting waste obtained by cutting or a powdered body thereof. [15] In the high-strength flame-retardant magnesium alloy according to claim 13,  The high-strength flame-retardant magnesium alloy characterized in that the plastic working is one type selected from extrusion processing, drawing processing, rotary forging processing and rolling processing, or a combination of two or more types. [16] In the high-strength flame-retardant magnesium alloy described in item 1 selected from claims 1 to 15, The alloy constituted by the addition of the additional additive is an alloy constituting the filler material. High strength flame retardant magnesium alloy.  [17] In the high-strength flame-retardant magnesium alloy according to claim 16,  The high-strength flame-retardant magnesium alloy, wherein the filler material is a linear or rod-shaped welding material.