CA1278709C - Method for producing a tungsten carbide tip punch - Google Patents
Method for producing a tungsten carbide tip punchInfo
- Publication number
- CA1278709C CA1278709C CA000518564A CA518564A CA1278709C CA 1278709 C CA1278709 C CA 1278709C CA 000518564 A CA000518564 A CA 000518564A CA 518564 A CA518564 A CA 518564A CA 1278709 C CA1278709 C CA 1278709C
- Authority
- CA
- Canada
- Prior art keywords
- tungsten carbide
- crown
- punch rod
- indentation
- carbide piece
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 title claims abstract description 65
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 238000007373 indentation Methods 0.000 claims abstract description 30
- 238000005219 brazing Methods 0.000 claims abstract description 29
- 239000000463 material Substances 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 11
- 238000002791 soaking Methods 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000002844 melting Methods 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 230000008569 process Effects 0.000 claims description 2
- 229910000997 High-speed steel Inorganic materials 0.000 claims 1
- 229910001315 Tool steel Inorganic materials 0.000 claims 1
- 230000003213 activating effect Effects 0.000 abstract description 3
- 238000004080 punching Methods 0.000 description 7
- 230000002045 lasting effect Effects 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- 229910052699 polonium Inorganic materials 0.000 description 2
- HZEBHPIOVYHPMT-UHFFFAOYSA-N polonium atom Chemical compound [Po] HZEBHPIOVYHPMT-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 2
- 229910018487 Ni—Cr Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Landscapes
- Mounting, Exchange, And Manufacturing Of Dies (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method is used for producing a tungsten carbide tip punch which includes a punch rod and a tungsten carbide piece of a hardness greater than that of the punch rod. A crown-like indentation is formed in the bottom surface of the tung-sten carbide piece. A brazing material is applied to the vertices of the crown-like indentation and around the inter-engaging surfaces of the punch rod and the tungsten carbide piece. The cylindrical protrusion of the top surface of the punch rod is pushed into the crown-like indentation of the tungsten carbide piece by a hydraulic activating apparatus so that the top of the cylindrical protrusion is formed, along the vertices, into a crown-like shape to join the punch rod and the tungsten carbide piece together. Both the brazing material and the interengaging surfaces are vacuum heated to enable flow of the molten brazing material over all the in-terengaging surfaces thus further bonding them together.
A method is used for producing a tungsten carbide tip punch which includes a punch rod and a tungsten carbide piece of a hardness greater than that of the punch rod. A crown-like indentation is formed in the bottom surface of the tung-sten carbide piece. A brazing material is applied to the vertices of the crown-like indentation and around the inter-engaging surfaces of the punch rod and the tungsten carbide piece. The cylindrical protrusion of the top surface of the punch rod is pushed into the crown-like indentation of the tungsten carbide piece by a hydraulic activating apparatus so that the top of the cylindrical protrusion is formed, along the vertices, into a crown-like shape to join the punch rod and the tungsten carbide piece together. Both the brazing material and the interengaging surfaces are vacuum heated to enable flow of the molten brazing material over all the in-terengaging surfaces thus further bonding them together.
Description
~'~78709 A METHOD FOR PRODUCING A TUNGSTEN CARBIDE TIP PUNCH
BACKGROUND OF THE INVENTION
The invention relates to a method Eor producing a punching tool, particularly to a method for producing one to the top of which a tungsten carbide piece is attached.
Nowadays, punching tools can be categorized into two types. One is made of tungsten carbide which has a high manufacturing cost and which is brittle by nature, which results in frequent tool breakage in use.
As shown in Fig. l, the othee type of punching tool includes a punch rod 4 and a tungsten carbide rod 3 having more than a third of the length thereof inserted into a well-matched corresponding hole provided on the punch rod 4 with a brazing material 34 joining them together. The latter type is an improvement over the former type; however, it still suffers from the following disadvantages:
1. It requires that the tungsten rod 3 have a suitable length in order that the rods 3 and 4 can be effectively joined together.
BACKGROUND OF THE INVENTION
The invention relates to a method Eor producing a punching tool, particularly to a method for producing one to the top of which a tungsten carbide piece is attached.
Nowadays, punching tools can be categorized into two types. One is made of tungsten carbide which has a high manufacturing cost and which is brittle by nature, which results in frequent tool breakage in use.
As shown in Fig. l, the othee type of punching tool includes a punch rod 4 and a tungsten carbide rod 3 having more than a third of the length thereof inserted into a well-matched corresponding hole provided on the punch rod 4 with a brazing material 34 joining them together. The latter type is an improvement over the former type; however, it still suffers from the following disadvantages:
1. It requires that the tungsten rod 3 have a suitable length in order that the rods 3 and 4 can be effectively joined together.
2. It is necessary to accurately work the corresponding hole for tightly fitting the tungsten carbide rod therein so that the punching tool can be ~L~78709 durable. Nevertheless, such a punching tool still does not have sufficient strength and necessitates frequent replacement which, in turn, inevitably reduces efficiency.
3. Owing to the difference in material, the carbide rod 3 is broken easily where it joins the peripheral portion of the bottom of the corresponding hole because of stress concentration.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a method for producing a tungsten carbide tip punch, which has a low manufacturing cost and by which the tungsten carbide tip punch has high wear, deformation, deflection and impact resistance through a firm fusible metallic bonding process.
According to the invention, a method for producing a tungsten carbide tip punch comprises the steps of: (1) preparing a punch rod including a top surface having a cylindrical protrusion projecting:from the top surface; (2) placing on the top surface of the punch rod a tungsten carbide piece having a hardness greater than that of the punch rod, the tungsten carbide piece including a bottom surface having a crown-like indentation which, at the bottom surface, has an opening of a diameter larger slightly than that of the cylindrical protrusion and which is capable of being well matched with the cylindrical protrusion of 1'~78~
the punch rod at the lowermost portion of the crown-like indentation, the crown-like indentation having a maximum diameter at a portion other than the opening of the crown-like indentation; (3) applying a brazing S material on each of the vertices of the crown-like indentation of the tungsten carbide piece and around interengaging surfaces of said punch rod and said tungsten carbide piece; (4) pushing mechanically the cylindrical protrusion of the punch rod into the crown-like indentation of the tungsten carbide~-piece so that the top of the cylindrical protrusion deforms along the vertices of the crown-like indentation of the tungsten carbide piece into a crown-like shape to join the punch piece and the tungsten carbide piece together; and (5).
vacuum heating the brazing material for flow of the molten brazing material over all the interengaging surfaces of the punch piece and the tungsten carbide piece to further bond the punch and tungsten carbide pieces together. --Furthermore, for convenience of the mechanical jointing of the punch rod with the tungsten carbide piece and of the application of the brazing material, the punch piece may be secured into a tube secured on a securing structure during the joint.
In the step of the vacuum heating of the brazing material, according to the prior application, the flow of the molten brazing material is over only a part of 1'~78709 the interengaging surfaces of the punch rod and the tungsten carbide piece. Now, according to the invention, it is over all the interengaging surfaces so that firm bonding is apparently obtained. This is the improvement of the invention over the prior application.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view showing a tungsten carbide tip punch produced by a method according to the prior art;
Fig. 2 is a sectional view showing a punch rod and a tungsten carbide piece for assembly of a punching tungsten carbide tip punch produced by a method according to the invention; and Fig. 3 is a sectional view showing the punching tungsten carbide tip punch assembled of the punch rod and the tungsten carbide piece of Fig. 2, produced by the method according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 2, a tungsten carbide tip punch produced by a method according to the invention is assembled from a punch rod 11 including a top surface 111 having a cylindrical protrusion 112 projecting from the central portion of the top surface 111, and a tungsten carbide piece 12 including a bottom surface 121 having a crown-like indentation 122 which is provided with two arched vertices and which is indented .
~7a70~3 from the central portion of the lower surface 121 for engaging with the cylindrical protrusion 112 of the punch rod 11. The diameter of the crown-like indentation 122 is smallest at the opening thereof.
A typical material of the punch rod 11 may be SKH-9 or SKD-ll (in Japanese Industrial Standard) where SKD-ll comprises 1.4 - 1.6% Carbon, 0.15 - 0.35%
Silicon, 0.3 - 0.6% Manganese, 11 - 13% Chromium, 0.2 -0.5% Vanadium, 0.8 - 1.2% Molybdenum, 0.05% Polonium, and 0.01% Sulfur, and where SKH-9 comprises 0.8 - 0.9%
Carbon, 0.45% Manganese, 3.8 - 4.5% Chromium, 1.6 -2.2% Vanadium, 4.5 - 5.5 Molybdenum, 0.03% Polonium, 0.01 Sulfur, and 5.5 - 6.7% Wolfram.
The tungsten carbide 12 has a composition comprising 82% Wolfram Carbide and 18% Cobalt, and has a thickness of from about 3.5mm to about 7mm.
Additionally, the preferred relation between the punch piece 11 and the tungsten carbide 12 in size with reference to Figs. 2 and 3 is as f~llows:
dl= from D/3 to D/2 d2- dl + 0.3mm d3 dl - O.lmm h2 = hl - O.lmm where D is the outer diameter of the tungsten carbide piece 12, dl is the diameter of the opening of the crown-like indentation of the tungsten carbide piece 12, d2 is the maximum diameter of the crown-like ~78~9 indentation of the tungsten carbide piece 12, d3 is the diameter of the cylindrical protrusion 112 of the punch rod 11, hl is the height of the cylindrical protrusion 112 of the punch rod, and h2 is the central depth of the crown-like indentation 122 of the tungsten carbide piece 12.
After completion of preparing the punch rod 11 and the tungsten carbide piece 12, a brazing material is applied on the vertices of the crown-like indentation 122 of the tungsten carbide piece 12 and around the interengaging surfaces on the two pieces 11 and 12. The applied brazing material may be, for example, a Ni-Cr alloy powder mixed in acetone.
A layer of STOP-OFF powder is then applied respectively around the brazing material applied around the interengaging surfaces on the punch rod ll and the tungsten carbide piece 12 to prevent capillary action of the brazing material when melting within the interengaging surfaces.
Subsequently, the jointing of the punch rod ll and the tungsten carbide piece 12 is effected.
Because the tungsten carbide piece 12 has a hardness of HRA ~Hardness Rockwell A) 82-86 degrees, while the punch piece 11 has a hardness of only HRC
(Hardness Rockwell C) 10-20 degrees, when the cylindrical protrusion 112 of the punch rod 11 is pushed into the crown-like indentation 122 of the ~ ,~7870~
tungsten carbide piece 12 by a hydraulic activating apparatus (not shown), the top portion of the cylindrical protrusion 112 will deform along the arched vertices of the crown-like indentation 122 into a crown-like shape for fitting tightly into the crown-like indentation 122 of the tungsten carbide piece 12.
Certainly, for convenience of effecting fully the jointing of the punch rod 11 and the tungsten carbide piece 12, the punch rod 11 may be, when jointed, secured into a circular tube secured .on a securing structure, described in the prior application.
The last step of the invention is putting the snap fitting assembly of punch rod 11 and tungsten carbide piece 12 into a vacuum heating apparatus, such as Model FHH-45G~I manufactured by Nihon Punch Shinku Kabushiki Kaishiya in Japan, to melt the brazing material applied on the assembly for flow of the molten brazing material over all the interengaging surfaces so as to further bond the punch rod 11 and the tungsten carbide piece 12 together by the melten brazing material. It is understood that the molten brazing material can flow over all the interengaging surfaces because it can flow capillæily along the arched vertexes of the indentation 122.
The last step described in the embodiment further includes in turn five successive sub-steps of:
(1) putting the assembly of the punch rod 11 and 1~78709 the tungsten carbide piece 12, assembled mechanically by the hydraulic activating apparatus, (described as the assembly hereinafter) into a vacuum heating apparatus having a vacuum maintained at about 0.3 Torr;
(2) soaking the assembly at a temperature of 450C - 550C;
(3) soaking the assembly at a temperature of 700C - 850C;
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a method for producing a tungsten carbide tip punch, which has a low manufacturing cost and by which the tungsten carbide tip punch has high wear, deformation, deflection and impact resistance through a firm fusible metallic bonding process.
According to the invention, a method for producing a tungsten carbide tip punch comprises the steps of: (1) preparing a punch rod including a top surface having a cylindrical protrusion projecting:from the top surface; (2) placing on the top surface of the punch rod a tungsten carbide piece having a hardness greater than that of the punch rod, the tungsten carbide piece including a bottom surface having a crown-like indentation which, at the bottom surface, has an opening of a diameter larger slightly than that of the cylindrical protrusion and which is capable of being well matched with the cylindrical protrusion of 1'~78~
the punch rod at the lowermost portion of the crown-like indentation, the crown-like indentation having a maximum diameter at a portion other than the opening of the crown-like indentation; (3) applying a brazing S material on each of the vertices of the crown-like indentation of the tungsten carbide piece and around interengaging surfaces of said punch rod and said tungsten carbide piece; (4) pushing mechanically the cylindrical protrusion of the punch rod into the crown-like indentation of the tungsten carbide~-piece so that the top of the cylindrical protrusion deforms along the vertices of the crown-like indentation of the tungsten carbide piece into a crown-like shape to join the punch piece and the tungsten carbide piece together; and (5).
vacuum heating the brazing material for flow of the molten brazing material over all the interengaging surfaces of the punch piece and the tungsten carbide piece to further bond the punch and tungsten carbide pieces together. --Furthermore, for convenience of the mechanical jointing of the punch rod with the tungsten carbide piece and of the application of the brazing material, the punch piece may be secured into a tube secured on a securing structure during the joint.
In the step of the vacuum heating of the brazing material, according to the prior application, the flow of the molten brazing material is over only a part of 1'~78709 the interengaging surfaces of the punch rod and the tungsten carbide piece. Now, according to the invention, it is over all the interengaging surfaces so that firm bonding is apparently obtained. This is the improvement of the invention over the prior application.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view showing a tungsten carbide tip punch produced by a method according to the prior art;
Fig. 2 is a sectional view showing a punch rod and a tungsten carbide piece for assembly of a punching tungsten carbide tip punch produced by a method according to the invention; and Fig. 3 is a sectional view showing the punching tungsten carbide tip punch assembled of the punch rod and the tungsten carbide piece of Fig. 2, produced by the method according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 2, a tungsten carbide tip punch produced by a method according to the invention is assembled from a punch rod 11 including a top surface 111 having a cylindrical protrusion 112 projecting from the central portion of the top surface 111, and a tungsten carbide piece 12 including a bottom surface 121 having a crown-like indentation 122 which is provided with two arched vertices and which is indented .
~7a70~3 from the central portion of the lower surface 121 for engaging with the cylindrical protrusion 112 of the punch rod 11. The diameter of the crown-like indentation 122 is smallest at the opening thereof.
A typical material of the punch rod 11 may be SKH-9 or SKD-ll (in Japanese Industrial Standard) where SKD-ll comprises 1.4 - 1.6% Carbon, 0.15 - 0.35%
Silicon, 0.3 - 0.6% Manganese, 11 - 13% Chromium, 0.2 -0.5% Vanadium, 0.8 - 1.2% Molybdenum, 0.05% Polonium, and 0.01% Sulfur, and where SKH-9 comprises 0.8 - 0.9%
Carbon, 0.45% Manganese, 3.8 - 4.5% Chromium, 1.6 -2.2% Vanadium, 4.5 - 5.5 Molybdenum, 0.03% Polonium, 0.01 Sulfur, and 5.5 - 6.7% Wolfram.
The tungsten carbide 12 has a composition comprising 82% Wolfram Carbide and 18% Cobalt, and has a thickness of from about 3.5mm to about 7mm.
Additionally, the preferred relation between the punch piece 11 and the tungsten carbide 12 in size with reference to Figs. 2 and 3 is as f~llows:
dl= from D/3 to D/2 d2- dl + 0.3mm d3 dl - O.lmm h2 = hl - O.lmm where D is the outer diameter of the tungsten carbide piece 12, dl is the diameter of the opening of the crown-like indentation of the tungsten carbide piece 12, d2 is the maximum diameter of the crown-like ~78~9 indentation of the tungsten carbide piece 12, d3 is the diameter of the cylindrical protrusion 112 of the punch rod 11, hl is the height of the cylindrical protrusion 112 of the punch rod, and h2 is the central depth of the crown-like indentation 122 of the tungsten carbide piece 12.
After completion of preparing the punch rod 11 and the tungsten carbide piece 12, a brazing material is applied on the vertices of the crown-like indentation 122 of the tungsten carbide piece 12 and around the interengaging surfaces on the two pieces 11 and 12. The applied brazing material may be, for example, a Ni-Cr alloy powder mixed in acetone.
A layer of STOP-OFF powder is then applied respectively around the brazing material applied around the interengaging surfaces on the punch rod ll and the tungsten carbide piece 12 to prevent capillary action of the brazing material when melting within the interengaging surfaces.
Subsequently, the jointing of the punch rod ll and the tungsten carbide piece 12 is effected.
Because the tungsten carbide piece 12 has a hardness of HRA ~Hardness Rockwell A) 82-86 degrees, while the punch piece 11 has a hardness of only HRC
(Hardness Rockwell C) 10-20 degrees, when the cylindrical protrusion 112 of the punch rod 11 is pushed into the crown-like indentation 122 of the ~ ,~7870~
tungsten carbide piece 12 by a hydraulic activating apparatus (not shown), the top portion of the cylindrical protrusion 112 will deform along the arched vertices of the crown-like indentation 122 into a crown-like shape for fitting tightly into the crown-like indentation 122 of the tungsten carbide piece 12.
Certainly, for convenience of effecting fully the jointing of the punch rod 11 and the tungsten carbide piece 12, the punch rod 11 may be, when jointed, secured into a circular tube secured .on a securing structure, described in the prior application.
The last step of the invention is putting the snap fitting assembly of punch rod 11 and tungsten carbide piece 12 into a vacuum heating apparatus, such as Model FHH-45G~I manufactured by Nihon Punch Shinku Kabushiki Kaishiya in Japan, to melt the brazing material applied on the assembly for flow of the molten brazing material over all the interengaging surfaces so as to further bond the punch rod 11 and the tungsten carbide piece 12 together by the melten brazing material. It is understood that the molten brazing material can flow over all the interengaging surfaces because it can flow capillæily along the arched vertexes of the indentation 122.
The last step described in the embodiment further includes in turn five successive sub-steps of:
(1) putting the assembly of the punch rod 11 and 1~78709 the tungsten carbide piece 12, assembled mechanically by the hydraulic activating apparatus, (described as the assembly hereinafter) into a vacuum heating apparatus having a vacuum maintained at about 0.3 Torr;
(2) soaking the assembly at a temperature of 450C - 550C;
(3) soaking the assembly at a temperature of 700C - 850C;
(4) soaking the assembly at a temperature of 900 C - 1030 C; and (5) heating the assembly tv a temperature of 25 C - 100 C over the melting point of the brazing material.
The time spent in each of Sub-steps (2)-(4) is about half an hour and the time spent in Sub-step (5) is 10 - 30 minutes.
After Sub-step (5) is performed, the assembly is sent to a cooling chamber and then is subjected to a tempering treatment. For the SKH-9 punch rod 11, the tempering treatment is done three times at a temperature of 540 c- 580 C, each time lasting 1 hr.
For the SKD-ll punch rod 11, the tempering treatment is done twice at a temperature of 150 C- 220 C, each time lasting lasting 1 hr. Certainly, each of the interengaging surfaces should be well pre-ground.
In addition to the initial mechanical joint, according to the invention, subsequent brazing process 1'~787~
is effected over all the-interengaging surfaces of the punch rod 11 and the tungsten carbide piece 12. Thus, the tungsten carbide tip punch after the mechanical joint and particularly the brazing is very solid and durable. The above-mentioned object is therefore achieved by the method of the invention.
With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the invention be limited as indicated in the appended claims.
The time spent in each of Sub-steps (2)-(4) is about half an hour and the time spent in Sub-step (5) is 10 - 30 minutes.
After Sub-step (5) is performed, the assembly is sent to a cooling chamber and then is subjected to a tempering treatment. For the SKH-9 punch rod 11, the tempering treatment is done three times at a temperature of 540 c- 580 C, each time lasting 1 hr.
For the SKD-ll punch rod 11, the tempering treatment is done twice at a temperature of 150 C- 220 C, each time lasting lasting 1 hr. Certainly, each of the interengaging surfaces should be well pre-ground.
In addition to the initial mechanical joint, according to the invention, subsequent brazing process 1'~787~
is effected over all the-interengaging surfaces of the punch rod 11 and the tungsten carbide piece 12. Thus, the tungsten carbide tip punch after the mechanical joint and particularly the brazing is very solid and durable. The above-mentioned object is therefore achieved by the method of the invention.
With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the invention be limited as indicated in the appended claims.
Claims (3)
1. A method for producing a tungsten carbide tip punch com-prising: (1) preparing a punch rod made of tool steel or high speed steel including a top surface having a cylindrical pro-trusion; (2) placing on said top surface of said punch rod a tungsten carbide piece including a bottom surface having a crown-like indentation with a plurality of vertices which has at said bottom surface an opening of a diameter slightly larg-er than that of said cylindrical protrusion and which has a size relative to said cylindrical protrusion capable of being well-matched with said cylindrical protrusion at a lowermost portion of said crown-like indentation, said crown-like inden-tation having a maximum diameter at an other portion than said opening; (3) applying a brazing material on each of said ver-tices of said crown-like indentation of said tungsten carbide piece; (4) pushing mechanically said cylindrical protrusion of said punch rod into said crown-like indentation of said tung-sten carbide piece so that an uppermost portion of said cylin-drical protrusion deforms along said vertices of said crown-like indentation into a crown-like shape to join said punch rod and said tungsten carbide piece together; (5) applying a brazing material around all interengaging surfaces of said punch rod and said tungsten carbide piece; (6) soaking said brazing material in a vacuum maintained at about 0.3 Torr step by step to about 1030°, and continuously heating to a tempera-ture of 25°C-100°C above the melting point of said brazing material for 10-30 minutes so that said brazing material is molten to flow by capillary action over all said interengaging surfaces of said punch rod and said tungsten carbide piece to further bond said punch rod and said tungsten carbide piece together; and (7) keeping an assembly of said punch rod and said tungsten carbide piece in a cooling chamber so that said punch rod is quenchd and thus hardened.
2. A method as claimed in Claim 1, wherein said size of said crown-like indentation relative to said cylindrical pro-trusion is subjected to the relation of:
d1= from D/3 to D/2 d2 ? d1 + 0.3mm d3 ? d1 - 0.1mm h2 = h1 - 0.1mm where D is the outer diameter of said tungsten carbide piece, d1 is the diameter of the opening of said crown-like indenta-tion of said tungsten carbide piece, d2 is the maximum diame-ter of said crown-like indentation of said tungsten carbide piece, d3 is the diameter of said cylindrical protrusion of said punch rod, h1 is the height of said cylindrical protru-sion of said punch rod, and h2 is the central depth of said crown-like indentation of said tungsten carbide piece.
d1= from D/3 to D/2 d2 ? d1 + 0.3mm d3 ? d1 - 0.1mm h2 = h1 - 0.1mm where D is the outer diameter of said tungsten carbide piece, d1 is the diameter of the opening of said crown-like indenta-tion of said tungsten carbide piece, d2 is the maximum diame-ter of said crown-like indentation of said tungsten carbide piece, d3 is the diameter of said cylindrical protrusion of said punch rod, h1 is the height of said cylindrical protru-sion of said punch rod, and h2 is the central depth of said crown-like indentation of said tungsten carbide piece.
3. A method as claimed in Claim 1, wherein a soaking pro-cess of step (6) comprises in turn three successive sub-steps:
(1) soaking said brazing material and said interengaging sur-faces at a temperature of 450°C-550°C; and (2) soaking said brazing material and said interengaging surfaces at a tempera-ture of 700°C-850°C; and (3) soaking said brazing material and said interengaging surfaces at a temperature of 900°C-1030°C;
the time spent in each of said sub-steps being about half an hour.
(1) soaking said brazing material and said interengaging sur-faces at a temperature of 450°C-550°C; and (2) soaking said brazing material and said interengaging surfaces at a tempera-ture of 700°C-850°C; and (3) soaking said brazing material and said interengaging surfaces at a temperature of 900°C-1030°C;
the time spent in each of said sub-steps being about half an hour.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000518564A CA1278709C (en) | 1986-09-18 | 1986-09-18 | Method for producing a tungsten carbide tip punch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000518564A CA1278709C (en) | 1986-09-18 | 1986-09-18 | Method for producing a tungsten carbide tip punch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1278709C true CA1278709C (en) | 1991-01-08 |
Family
ID=4133971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000518564A Expired - Lifetime CA1278709C (en) | 1986-09-18 | 1986-09-18 | Method for producing a tungsten carbide tip punch |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1278709C (en) |
-
1986
- 1986-09-18 CA CA000518564A patent/CA1278709C/en not_active Expired - Lifetime
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4722125A (en) | Method for producing a tungsten carbide tip punch | |
| US5435965A (en) | Sputtering target and method for manufacturing same | |
| CN100415434C (en) | Machine tool tool and method for its manufacture and solder lugs suitable therefor | |
| US5048375A (en) | Method for constructing a rotating cutting tool | |
| EP0183902A2 (en) | Method of attaching segments to cutting tool | |
| US20090019890A1 (en) | Method of Assembling a Metal Bracelet | |
| JP4244072B2 (en) | Machine tool and manufacturing method thereof | |
| EP1527842B1 (en) | A method of manufacturing a fibre reinforced metal matrix composite article | |
| US5076484A (en) | Joining structure of a turbine rotor | |
| US20080045991A1 (en) | Joining Ceramics To Metal | |
| US6592287B1 (en) | Self-fixtured joint assembly and its preparation | |
| CA1278709C (en) | Method for producing a tungsten carbide tip punch | |
| US4873895A (en) | Manufacture of rotary drill bits | |
| KR100894049B1 (en) | Use in the manufacture of brazing foil preforms and heat exchangers | |
| US20090032572A1 (en) | System, method, and apparatus for reactive foil brazing of rock bit components. Hardfacing and compacts | |
| EP0211347B1 (en) | Rotary shaft assembly and method for joining a shaft portion of ceramics construction with a boss portion of metal construction | |
| US3089353A (en) | Method for making a router bit or the like | |
| US4445810A (en) | Method of making a cutting member and article produced thereby | |
| KR910000517B1 (en) | Method for producing a tungsten carbide tip punch | |
| US3768342A (en) | Connecting metal elements and products thereof | |
| JP2693973B2 (en) | Diffusion bonding method for tubular laminated materials | |
| JPS59183985A (en) | Welding tip and its production | |
| US4659897A (en) | Method of making a watchcase | |
| DE3703900A1 (en) | ROTATING TOOL | |
| KR100306493B1 (en) | Diffusion joint method of puberty material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |