CN105537703A - Laminated fitting preparing method for three-dimensional microelectrode - Google Patents

Abstract

The invention proposes a three-dimensional microelectrode stack fitting preparation method, by making part models, establishing three-dimensional microelectrode models, establishing sheet electrode data models, setting three-dimensional microelectrode parameters, processing three-dimensional microelectrodes, and thermal diffusion welding three-dimensional microelectrodes After the step, a three-dimensional stacked microelectrode profile is formed. And the machining accuracy can be improved by further grinding steps. The invention solves the technical problem that the three-dimensional microelectrode is difficult to prepare, and the three-dimensional microstructure can be obtained through simple up-and-down reciprocating processing, the processing process is simple and the efficiency is high; at the same time, the three-dimensional laminated microelectrode The steps of the electrode are effectively eliminated, improving the surface quality of the workpiece.

Description

A three-dimensional microelectrode stack fitting preparation method

technical field

The invention relates to a three-dimensional microelectrode processing method for micro electric discharge machining or micro electrolytic machining.

Background technique

Generally, microstructure is defined as: at least on a two-dimensional scale, a product with a submillimeter or micron-scale micro-feature structure is called a micro (structural) part.

Micro electric discharge machining or micro electrolytic machining through micro electrodes is the mainstream processing method for preparing three-dimensional microstructures. The process is specifically:

A two-dimensional semi-cylindrical microelectrode with a small diameter is fabricated by various processing methods, and then a three-dimensional microstructure is obtained by layer-by-layer scanning discharge machining or electrolytic machining of the microelectrode. However, because the diameter of the cylindrical microelectrode is very small relative to the scanning area, the processing efficiency is very low. Moreover, during the layer-by-layer scanning discharge machining process of the micro-electrode, the wear of the micro-electrode is very serious, and it is difficult to work normally for a long time.

Contents of the invention

The technical problem to be solved by the present invention is to make up for the above-mentioned defects in the prior art, and to provide a method for forming a three-dimensional microelectrode for micro electric discharge machining or micro electrolytic machining.

Technical problem of the present invention is solved by following technical scheme:

A kind of three-dimensional microelectrode lamination fitting preparation method, it comprises the following steps:

Step 1: Make a part model; draw the three-dimensional microstructure geometric model of the part to be prepared;

Step 2: Establish a three-dimensional microelectrode model; according to the three-dimensional microstructure geometric model, establish a three-dimensional microelectrode geometric model of the model for electric discharge machining, and perform discrete slices on the three-dimensional microelectrode geometric model to obtain a discrete slice geometric model;

Step 3: Establish a sheet electrode data model; convert the discrete slice geometric model into a set of parallel sheet electrode data models; the number of sheet electrodes in the sheet electrode data model is the same as the slice number in the discrete slice geometric model N is equal, the thickness of the sheet electrode is equal to the thickness H of the slice;

Step 4: Set the parameters of the three-dimensional microelectrode; set the number of layers, layer thickness and contour data of the three-dimensional microelectrode according to the number of slices N, the thickness H, and the track data of the sheet electrode;

Step 5: Process the three-dimensional microelectrodes; clamp and fix a group of metal foils, the thickness of the metal foils is the same as the thickness H in the step 4; fix the first layer of single metal foil, and the remaining layers are to be The processed metal foil is bent upwards under the action of external force, and fixed by the first stopper; it is processed into the microelectrode contour corresponding to the first layer through wire cutting or laser cutting process; after the microelectrode contour of the first layer is processed, it is function, make it bend downwards, and block it with the second stopper;

Step 6: Process the three-dimensional microelectrode; fix the second layer of single-piece metal foil, and the remaining layers of metal foil to be processed are bent upward under the action of external force, and are blocked and fixed by the first stopper; processed by wire cutting or laser cutting To correspond to the microelectrode profile of the second layer; after the microelectrode profile of the second layer is processed, it is bent downward by an external force and blocked by a second stopper; this step is repeated in turn until each layer of metal foil Processed into two-dimensional sheet microelectrode contours for each layer;

Step 7: thermal diffusion welding of three-dimensional microelectrodes; put the multi-layer two-dimensional sheet microelectrodes that are still in the clamping state after processing into a vacuum furnace, and perform vacuum pressure thermal diffusion welding to make each layer of two-dimensional thin sheet microelectrodes completely Connect to form a three-dimensional microelectrode; the pressure of the vacuum furnace is P≤10Pa, the welding temperature T is 0.5 to 0.8 times the melting point of the three-dimensional electrode material, and the holding time is t≥1 hour. After completion, it is cooled with the furnace to form a three-dimensional laminated microelectrode contour.

In order to further improve the machining accuracy, preferably, the present invention further includes a grinding step of the contour of the three-dimensional laminated microelectrode:

Step 8: According to the gap between the geometric model of the 3D microelectrode designed in step 2 and the contour of the 3D laminated microelectrode actually prepared, design the grinding curve; perform EDM on the 3D laminated microelectrode containing steps Grind the step to a smooth curve.

Preferably, the metal foil is copper foil or nickel foil or molybdenum foil.

The thickness of the slice may be uniform or non-uniform, which may be specifically determined according to the fitting accuracy of the laminated electrodes. Preferably, the thickness of the slice is uniform, and the thickness H of the slice is ≤500 μm; preferably, the layer thickness h of the two-dimensional sheet microelectrode is ≤1.0 mm.

The beneficial effect that the present invention compares with prior art is:

1) The present invention proposes for the first time that a three-dimensional microelectrode is formed by lamination of multi-layer two-dimensional sheet microelectrodes, which effectively solves the technical problem that the three-dimensional microelectrode is difficult to prepare.

2) Three-dimensional microstructures can be prepared by using three-dimensional microelectrodes for micro-EDM or micro-electrolytic machining. Compared with the layer-by-layer scanning electrical discharge machining or layer-by-layer scanning electrolytic machining of the three-dimensional microstructure of the micro-electrode with a simple cross-sectional shape, the three-dimensional microelectrode can obtain the three-dimensional microstructure only by simple up-and-down reciprocating processing. Simple and high processing efficiency.

3) When the three-dimensional stacked microelectrodes with steps are directly used in micro-EDM or micro-electrolytic machining, the steps will be copied to the machining results, thereby affecting the shape accuracy and surface quality of the machining results. The steps of the three-dimensional laminated microelectrodes are effectively eliminated by forming EDM. Using the three-dimensional laminated microelectrodes that have been ground by EDM for micro-EDM or micro-electrolytic machining can effectively improve the shape accuracy of the machining results and improve the surface quality of the machining results.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative labor;

Fig. 1 is a schematic diagram of the geometric model of the required three-dimensional microstructure;

Fig. 2 is the schematic diagram of the geometric model of the three-dimensional microelectrode designed according to Fig. 1;

Fig. 3 is a schematic diagram of a discrete slice geometric model of a three-dimensional microelectrode;

Fig. 4 is a schematic diagram of the stack fitting forming of three-dimensional electrodes;

Fig. 5 is the EDM grinding principle of the three-dimensional laminated microelectrode;

Fig. 6 is the process of reducing the step effect by electric spark grinding;

Explanation of reference numerals: stopper 1, copper foil being processed 2, copper foil to be processed 3, clamping end 4, processed copper foil 5, cutting tool 6, two-dimensional sheet microelectrode 7, step 8, grinding Tool 9, ground part 10, unground part 11, three-dimensional laminated electrode 12, grinding direction A; electrode design model contour 13, laminated microelectrode rough machining actual contour 14, shaped grinding direction B.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The three-dimensional microelectrode stack fitting preparation method proposed by the present invention comprises the following steps:

Step 1: making a part model; drawing a three-dimensional microstructure geometric model of the part to be prepared; this step is generally completed by three-dimensional computer software;

Step 2: Establish a three-dimensional microelectrode model; according to the three-dimensional microstructure geometric model, establish a three-dimensional microelectrode geometric model of the model for electric discharge machining, and perform discrete slices on the three-dimensional microelectrode geometric model to obtain a discrete slice geometric model;

Step 3: Establish a sheet electrode data model; convert the discrete slice geometric model into a set of parallel sheet electrode data models; the number of sheet electrodes in the sheet electrode data model is the same as the slice number in the discrete slice geometric model N is equal, the thickness of the sheet electrode is equal to the thickness H of the slice;

Step 4: Set the parameters of the three-dimensional microelectrode; set the number of layers, layer thickness and contour data of the three-dimensional microelectrode according to the number of slices N, the thickness H, and the track data of the sheet electrode;

The computer divides the thickness of the three-dimensional microstructure geometric model by the layer thickness of the microelectrode to obtain the number of slices N (ie, the number of layers), thereby obtaining the number of layers and the layer thickness of the two-dimensional sheet microelectrode. Since the two-dimensional thin-sheet microelectrode is obtained by discretely slicing the geometric model of the three-dimensional microelectrode, the slice contains the contour data of the two-dimensional thin-sheet microelectrode, which is the basis for processing the two-dimensional thin-sheet electrode.

Step 5: Process the three-dimensional microelectrodes; clamp and fix a group of metal foils, the thickness of the metal foils is the same as the thickness H in the step 4; fix the first layer of single metal foil, and the remaining layers are to be The processed metal foil is bent upwards under the action of external force, and fixed by the first stopper; it is processed into the microelectrode contour corresponding to the first layer through wire cutting or laser cutting process; after the microelectrode contour of the first layer is processed, it is function, make it bend downwards, and block it with the second stopper;

Step 6: Process the three-dimensional microelectrode; fix the second layer of single-piece metal foil, and the remaining layers of metal foil to be processed are bent upward under the action of external force, and are blocked and fixed by the first stopper; processed by wire cutting or laser cutting To correspond to the microelectrode profile of the second layer; after the microelectrode profile of the second layer is processed, it is bent downward by an external force and blocked by a second stopper; this step is repeated in turn until each layer of metal foil Processed into two-dimensional sheet microelectrode contours for each layer;

The preliminary laminated three-dimensional microelectrode obtained in step six has no real connection between the two-dimensional sheet microelectrodes of each layer, so it is necessary to carry out vacuum pressure thermal diffusion welding in a vacuum furnace to complete the two-dimensional sheet microelectrodes of each layer The complete connection, the specific steps are as follows:

Step 7: thermal diffusion welding of three-dimensional microelectrodes; put the multi-layer two-dimensional sheet microelectrodes that are still in the clamping state after processing into a vacuum furnace, and perform vacuum pressure thermal diffusion welding to make each layer of two-dimensional thin sheet microelectrodes completely Connect to form a three-dimensional microelectrode; the pressure of the vacuum furnace is P≤10Pa, the welding temperature T is 0.5 to 0.8 times the melting point of the three-dimensional electrode material, and the holding time is t≥1 hour. After completion, it is cooled with the furnace to form a three-dimensional laminated microelectrode contour.

The initial profile of the 3D laminated microelectrode processed according to the above steps is composed of fine horizontal and vertical line segments (these line segments also constitute the steps of the 3D laminated microelectrode), and these steps are superimposed and fitted into a 3D laminated microelectrode Initial design outline. The steps of the three-dimensional laminated microelectrode will affect the shape accuracy of the laminated electrode, which can be eliminated by form grinding. Therefore the present invention can further comprise grinding step:

Step 8: According to the gap between the geometric model of the 3D microelectrode designed in step 2 and the contour of the 3D laminated microelectrode actually prepared, design the grinding curve; perform EDM on the 3D laminated microelectrode containing steps Grinding, grinding the step into a smooth curve; its specific process is as follows:

1) When the shape grinding starts, the step of the three-dimensional laminated microelectrode is a broken line, and the step contains concave points and convex points. The three-dimensional laminated microelectrode with steps is used for EDM grinding. Under the influence of the skin effect of the electrode, the loss of the bump is the fastest, and the loss is gradually slowed toward the direction of the concave points at both ends. The loss is the smallest; 2) With the gradual progress of EDM grinding, the steps are gradually ground into smooth curves, and at this time, the bumps of the three-dimensional laminated microelectrodes gradually change from sharp angles of 90° to smoother ones. Since the profile of the step gradually becomes a smoother curve, the grinding loss speed of the step gradually slows down, and at this time the difference in the loss speed between the top of the bump and other positions gradually decreases; 3) As the shape grinding continues , the steps of the three-dimensional microelectrode are continuously ground, and finally the contour of the three-dimensional laminated microelectrode is as close as possible to the contour of the electrode design model.

The thickness of the slices can be uniform or non-uniform, which is determined by the fitting accuracy of the stacked electrodes, and the thickness of the slices should be less than or equal to 500 μm. Preferably, the layer thickness h of the two-dimensional sheet microelectrode is ≤ 1.0 mm.

Embodiment 1: The electrode sheet material used in this embodiment is copper foil with a thickness of 0.1 mm.

The specific manufacturing process includes the following steps:

1. Establish a geometric model for the three-dimensional microstructure to be prepared, as shown in FIG. 1 .

2. Establish a geometric model of the three-dimensional micro-EDM electrode according to the geometric model of the three-dimensional microstructure, as shown in Figure 2, and perform discrete slices of the three-dimensional micro-electrode to obtain a discrete slice geometric model, as shown in Figure 3.

3. According to the above data, the lamination fitting forming process of the three-dimensional microelectrode is as follows: (1) Clamp and fix one end of a group of copper foils, which is the clamping end 4 . Copper foils are divided into processed copper foil 5, copper foil 2 being processed and copper foil 3 to be processed, as shown in Figure 4; 1 block, the other end of the copper foil 2 being processed is fixed by a fixture, and the two-dimensional sheet microelectrode 7 of this layer is cut and processed by the wire 6. The processed copper foil 5 needs to be elastically bent downward and used the second stopper 1 Blocking; (3) Repeat the above process until the processing of the two-dimensional sheet microelectrode 7 of each layer is completed. These two-dimensional sheet microelectrodes 7 are superimposed and fitted to obtain a preliminary stacked three-dimensional microelectrode; (4) the two-dimensional sheet microelectrodes of each layer of the preliminary stacked three-dimensional microelectrode are not really connected, so one end needs to be kept The three-dimensional microelectrodes in the clamped state and preliminarily stacked are placed in a vacuum furnace, and vacuum pressure thermal diffusion welding is performed on them, so as to complete the complete connection of the two-dimensional sheet microelectrodes of each layer. The atmospheric pressure of the vacuum furnace is 0.1Pa, the welding temperature is 850°C, the holding time is 10h, and it is cooled with the furnace.

4. The three-dimensional laminated electrode prepared by the above process is subjected to form grinding, as shown in Figure 5 and Figure 6, wherein 9 is a grinding tool, 10 is a ground part, 11 is an unground part, and 12 is a three-dimensional laminated electrode. Layer electrode, arrow A is the grinding direction, and the forming grinding direction is arrow B. The goal of EDM is to eliminate as much as possible the step 8 outside the double-dashed line in the electrode design model, and to make the prepared stacked microelectrode profile (that is, the stacked microelectrode represented by the single-dotted line part rough machine the actual profile 14) Approximate as much as possible to the electrode design model profile a _e s _e b _e (that is, the electrode design model profile 13 represented by the double-dashed line). The specific process of step grinding is described as follows: (1) When the shape grinding starts, the step a ₀ s ₀ b ₀ of the three-dimensional laminated microelectrode is a broken line, where a ₀ and b ₀ are the concave points of the step, and s ₀ is the step bumps. Under the influence of the electrode skin effect, the loss is the fastest at the convex point s ₀ , and the loss gradually slows down toward the direction of the concave points a ₀ and b ₀ at both ends, and the loss is the smallest at the concave points a ₀ and b ₀ ; (2) With the gradual progress of profile grinding, the step a ₀ s ₀ b ₀ is gradually ground into a smooth curve asb, at this time s ₀ gradually changes from a sharp angle of 90° to a smoother bump s. Since the profile of the step a ₀ s ₀ b ₀ gradually becomes a smoother curve asb, the grinding wear speed of the step gradually slows down, and at this time the difference in wear speed between the convex point s and other positions on the arc asb gradually decreases ; (3) As the form grinding continues, the steps of the 3D microelectrode continue to be ground, and finally the contour of the 3D laminated microelectrode is as close as possible to the contour of the electrode design model a _e s _e b _e .

5. The three-dimensional microelectrode prepared by the above process is applied to micro-EDM, and the three-dimensional microstructure can be obtained through the up and down reciprocating processing of the three-dimensional microelectrode, with high processing efficiency and low electrode loss.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (5)

1. a three-dimensional micro-electrode lamination matching preparation method, is characterized in that: it comprises the following steps:

Step one: make part model; Draw the three-dimensional microstructures geometrical model of part to be prepared;

Step 2: set up three-dimensional micro-electrode model; According to described three-dimensional microstructures geometrical model, set up the three-dimensional micro-electrode geometrical model of this model of spark machined, and described three-dimensional micro-electrode geometrical model is carried out discrete slices, obtain discrete slices geometrical model;

Step 3: set up thin electrode data model; Described discrete slices geometrical model is converted into one group of thin electrode data model be parallel to each other; Thin electrode quantity in described thin electrode data model is equal with the number of sections N in described discrete slices geometrical model, and the thickness of described thin electrode is equal with the thickness H of described section;

Step 4: three-dimensional micro-electrode parameter is set; Track data according to described number of sections N, thickness H, thin electrode arranges the number of plies of three-dimensional micro-electrode, thickness and outline data;

Step 5: machining 3 D microelectrode; One group of metal forming be fixedly clamped, the thickness of described metal forming is identical with the thickness H in described step 4; Maintained static by ground floor unitary piece of metal paper tinsel, all the other each layers metal forming to be processed is bent upwards under external force, and blocks fixing with the first block; The microelectrode profile of corresponding ground floor is processed as by Linear cut or laser cutting operation; After described ground floor microelectrode contour machining completes, by External Force Acting, make it be bent downwardly, and block with the second block;

Step 6: machining 3 D microelectrode; Maintained static by second layer unitary piece of metal paper tinsel, all the other each layers metal forming to be processed is bent upwards under external force, and blocks fixing with the first block; The microelectrode profile of the corresponding second layer is processed as by Linear cut or laser cutting operation; After described second layer microelectrode contour machining completes, by External Force Acting, make it be bent downwardly, and block with the second block; Repeat this step successively, until each layer metal forming to be processed as each layer two-dimensional slice microelectrode profile;

Step 7: thermodiffusion welding three-dimensional micro-electrode; Putting into vacuum drying oven by machining multilayer two-dimension thin slice microelectrode that is rear, that be still in clamp position, carrying out vacuum pressure thermodiffusion welding, each layer two-dimensional slice microelectrode is connected completely, forming three-dimensional micro-electrode; Pressure P≤the 10Pa of described vacuum drying oven, welding temperature T are 0.5 ~ 0.8 times of three-diemsnional electrode material melting point, temperature retention time t >=1 hour, with stove cooling after completing, form 3-D stacks microelectrode profile.

2. three-dimensional micro-electrode lamination matching preparation method as claimed in claim 1, is characterized in that: it comprises the grinding step of 3-D stacks microelectrode profile further:

Step 8: according to the three-dimensional micro-electrode geometrical model designed in step 2, and the gap between the actual 3-D stacks microelectrode profile prepared, design grinding curve; 3-D stacks microelectrode containing step is carried out Electro Spark Discharge Grinding, is level and smooth curve by described step grinding.

3. three-dimensional micro-electrode lamination matching preparation method as claimed in claim 1, is characterized in that: thickness H≤500 μm of described section.

4. three-dimensional micro-electrode lamination matching preparation method as claimed in claim 1, is characterized in that: described metal forming is Copper Foil or nickel foil or molybdenum foil.

5. three-dimensional micro-electrode lamination matching preparation method as claimed in claim 1, is characterized in that: the thickness h≤1.0mm of described two-dimensional slice microelectrode.