JP2005248325A - Method for producing magnesium composite material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a magnesium composite material made of a compression-molded body in which a raw material is efficiently refined and uniformly dispersed. <P>SOLUTION: As shown by (A) in Figure, in a state where a raw material M obtained by mixing magnesium alloy chips and silica powder is stored into a molding hole 11, a molding pin 21 is penetrated. The raw material M is consolidated without going toward molding holes 12 to 14 clogged with molding pins 22 to 24. Next, as shown by (B), (C) in the figure, the molding pin 22 is made into the state where it can be retreated, and the molding pin 21 is further penetrated, thus the raw material M is crumbled by shearing force and flows from a crossing section 19 to the molding hole 12. Similarly, the consolidation and crumbling by shearing force to the raw material M are performed at the molding holes 12, 13, 14 in order. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention processes a mixed raw material containing chips or granules of magnesium or magnesium alloy and a powdered additive, and obtains a compression molded body in which the mixed material is refined and the additive is uniformly dispersed. The present invention relates to a method for manufacturing a magnesium composite material.

In recent years, the use of magnesium alloy, which is the lightest alloy, has attracted attention. This magnesium alloy has disadvantages such as low hardness, low rigidity, wearability, and corrosiveness, but in order to compensate for the disadvantages, a magnesium composite material in which hard magnesium silicide (Mg ₂ Si) particles are dispersed has been developed. ing.

  In the known general manufacturing method of the magnesium composite material in which the magnesium silicide particles are dispersed, the magnesium alloy is melted or semi-melted, so that the crystal grains of the magnesium alloy are coarsened and there is a limit to improvement in strength. It was.

  Therefore, a method for producing a magnesium alloy as disclosed in Non-Patent Document 1 and Patent Document 1 has been developed. In this method, the press shown in FIG. 11 is used. In this press machine, a lower die is provided with a die 1 (mortar), and an upper die is provided with two types of forming pins 7 and 9. The die 1 has a bottomed cylindrical shape and has an accommodation space 5 with an open top. The upper mold is provided with a switching mechanism for alternately positioning the molding pins 7 and 9 directly above the die 1. One forming pin 7 has a flat lower surface, and its diameter is substantially equal to the inner diameter of the accommodation space 5 of the die 1. The other forming pin 9 has an elongated bar shape, and the diameter thereof is smaller than the inner diameter of the accommodation space 5.

  As shown in FIG. 11 (a), in the housing space 5, a magnesium alloy chip having a diameter of several millimeters is filled with silicon or silica powder having a particle size of several microns to several tens of microns (% by weight based on the mixed material). The mixed raw material M is filled.

  Next, as shown in FIGS. 11 (a) and 11 (b), the forming pin 7 is positioned immediately above the die 1 and then lowered to press the material M into a flat cylindrical shape.

  Next, after raising the molding pin 7 and switching the other molding pin 9 to be positioned directly above the die 1, the molding pin 9 is lowered as shown in FIGS. 11 (c) and 11 (d). And press-fitted into the center of the raw material M. As a result, the raw material M is extruded backward by the molding pin 9 and rises around the molding pin 9 to form a deep hole in the center.

  Next, after raising the forming pin 9 as shown in FIG. 11 (e), as shown in FIGS. 11 (f) and 11 (b), the forming pin 7 is positioned right above the die 1 and then lowered. The raw material M is compressed again. By the lowering of the forming pin 7, the raw material M is pressed and consolidated so that the surrounding raised portion is buried in a deep hole in the center, and becomes a flat cylindrical shape again.

  By repeating the deformation (consolidation, backward extrusion) by the forming pins 7 and 9 as described above, the magnesium alloy chip in the raw material M is refined, and the silicon powder is further refined and uniformly dispersed in the magnesium alloy. Is done. Finally, the raw material M is pressed and hardened to obtain a compression molded body. Such a construction method is referred to as bulk mechanical alloying (BMA) in this specification.

With the crystal grains refined and uniformly dispersed to the desired level as described above, the compression molded product is taken out and heated in a solid phase temperature region in an inert gas atmosphere or in a vacuum to perform extrusion molding. To do. Thereby, silicon and magnesium react and magnesium silicide (Mg ₂ Si) is deposited. This heating is performed at a temperature of 350 ° C. or higher at which the magnesium crystal grains can be reliably bonded and at a temperature lower than 520 ° C. which is lower than the melting point of magnesium and low enough to suppress the coarsening of the magnesium crystal grains. Further, the structure is densified by extrusion.

In the BMA method, the oxide film MgO formed on the surface of the magnesium alloy chip is mechanically destroyed and divided to form a new active magnesium surface, so that the reactivity between Si and the base material can be increased. . In the case of using silica (SiO _2), by heating the compacts, MgO is also deposited.

As described above, a magnesium composite material in which magnesium silicide is dispersed is obtained. This composite material is lightweight because magnesium is used as a base material, and mechanical strength, corrosion resistance, wear resistance, and the like can be remarkably improved by Mg ₂ Si finely and uniformly dispersed.
Magazine Altopia December 2002 issue (12 pages) WO2003 / 027342

However, in the above method, the raw material flows only in the volume of the press-fitted forming pin 9, and the stirring flow efficiency is poor, and further, the efficiency of miniaturization and uniform dispersion is poor.
Further, in the accommodation space 5 of the die 1, the movement of the raw material M hardly occurs in the vicinity of the bottom portion, in particular, the corner portion where the bottom portion and the cylindrical peripheral wall intersect, even when the deformation process by the molding pins 7 and 9 is repeated. Since it becomes a region where fineness and uniform dispersion caused by movement and compression do not progress, it is necessary to flip the compacted raw material every time the process is repeated a predetermined number of times.

  The present invention has been made in order to solve the above-described problems. In the method for producing a magnesium composite material, mixed raw materials containing magnesium or a magnesium alloy chip or granule and a powdered additive are crossed with each other. The mixed raw material is squeezed in one molding hole as the pressing member inserted into the molding hole moves forward and backward in a state where it is accommodated in a mold having a plurality of continuous linear molding holes. The mixed raw material is crushed and sent to another forming hole, and this compaction and crushing are repeated to obtain a compression molded body in which the mixed raw material is refined and the additive is uniformly dispersed. The gist.

More specifically,
Prepare a mold having a plurality of linear molding holes that intersect and cross each other, and a plurality of pressing members respectively inserted into these molding holes,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdered additive is accommodated in one of the plurality of forming holes, and the flow of the mixed raw material into all other forming holes is prohibited. In the state, by pressing one pressing member inserted into the one molding hole toward the back, a pre-stage step of pressing the mixed raw material in the one molding hole is performed,
Next, in a state where the other pressing member inserted into the other one forming hole can be retracted or retracted in advance, the one pressing member is further pushed inward to push the mixed raw material. Execute a subsequent process of feeding from the one forming hole to the other forming hole while breaking,
By repeating the preceding step and the latter step and finally executing the preceding step in any one of the forming holes, a compression molded body in which the mixed raw material is refined and the additive is uniformly dispersed is obtained.

  According to the above method, the mixed raw material can be refined and the additive can be uniformly dispersed by repeating the process of compacting and crushing the mixed raw material. Moreover, in the process that the mixed raw material that has been compacted passes through the intersections of the molding holes, it receives a large shearing force and frictional force in almost the entire cross-sectional area, so that the above-mentioned miniaturization and uniform dispersion can be performed efficiently, As a result, the desired fineness and uniform dispersion can be obtained even if the mixed raw material is compacted and crushed few times.

In the first aspect of the present invention,
Prepare a mold having a plurality of linear molding holes that intersect and cross each other, and a plurality of pressing members respectively inserted into these molding holes,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdered additive is accommodated in one of the plurality of forming holes, and the flow of the mixed raw material into all other forming holes is prohibited. In the state, by pressing one pressing member inserted into the one molding hole toward the back, a pre-stage step of pressing the mixed raw material in the one molding hole is performed,
Next, in a state where the other one pressing member inserted into the other one forming hole can be retracted or retracted in advance, the one pressing member is further pushed into the back to push the mixed raw material. Execute the subsequent process of feeding from the one forming hole to the other forming hole while breaking,
Next, by the pressing of the pressing member inserted into the other forming hole, the preceding step involving the compaction of the raw material fed into the other forming hole, and the subsequent step involving the crushing of the mixed material, Run
By repeating the preceding process and the succeeding process in a predetermined order for the plurality of pressing members, and finally executing the preceding process in one of the forming holes, the mixed raw material is refined and the additive is uniformly dispersed. A compressed compression molded body is obtained.

  According to the method of the first aspect, since the mixed raw material is pressed and crushed again in the forming hole into which the mixed raw material that has been crushed flows, the production efficiency can be further improved.

In the second aspect of the present invention,
Prepare a mold having a plurality of linear molding holes that intersect and cross each other, and a plurality of pressing members respectively inserted into these molding holes,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdery additive is contained in one selected forming hole, and the raw material is not allowed to flow into all other forming holes. The first step of pressing the one of the pressing members inserted into the selected molding hole toward the back to compress the mixed raw material in the selected molding hole is performed,
Next, in a state where the other one forming pin inserted into the other one forming hole can be retracted or has been retracted in advance, the selected forming pin is further pushed into the back, thereby mixing the raw material. Execute the subsequent process of feeding from the selected molding hole to the other molding hole while crushing,
Next, a return step of returning the mixed raw material of the other forming hole to the selected forming hole by pressing with a pressing member inserted into the other forming hole,
The above process is repeated, and finally the preceding process is executed in the selected molding hole, thereby obtaining a compression molded body in which the mixed raw material is refined and the additive is uniformly dispersed.

  According to the second aspect, the efficiency is lower than that of the first aspect, but instead, only one selected molding pin needs to be pressurized with a large load, so that the configuration of the apparatus is simplified. Can do.

  Preferably, the forming holes intersect each other at an angle of approximately 90 °. According to this, at the time of crushing of the mixed raw material, even though a larger shearing force and frictional force can be given to the mixed raw material, the mixed raw material is passed from one forming hole to another forming hole. , Can flow relatively smoothly.

In the first and second embodiments, when the intersecting angle of the forming holes forms an angle of approximately 90 °, the mold can be provided with two to six forming holes as a plurality of forming holes.
In the first aspect, when two molding holes are provided, the mixed raw material can be miniaturized and uniformly dispersed with a very simple configuration. Specifically, it is as follows.
Preparing a mold having linear first and second molding holes that intersect and cross each other at approximately 90 °, and first and second pressing members respectively inserted into the first and second molding holes;
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdery additive is contained in the first forming hole, and the second pressing member is fixed at the back end of the second forming hole. The second forming hole is closed by this, and in this state, the first pressing member is pushed toward the back of the first forming hole, thereby executing a pre-stage step of pressing and solidifying the mixed raw material accommodated in the first forming hole,
Next, in a state in which the second pressing member can be retracted or retracted in advance, the first pressing member is further pushed into the back so that the mixed raw material is crushed and the second molding is performed from the first forming hole. Execute the latter stage process to feed into the hole,
Next, the first pressing member is fixed at the back end of the first forming hole to close the first forming hole, and in this state, the second pressing member is pushed toward the back of the second forming hole, Performing a pre-stage step of pressing and solidifying the mixed raw material accommodated in the second forming hole;
Next, in a state where the first pressing member can be retracted or retracted in advance, the second pressing member is further pushed into the back, so that the first raw material is pressed from the second forming hole while collapsing the mixed material. Execute the latter stage process to feed into the hole,
The above pre-stage process and post-stage process are alternately and repeatedly executed for the first and second pressing members, and finally the pre-stage process is executed in any one of the forming holes, whereby the mixed raw material is refined and the additive is uniform A compression molded body of the mixed raw material dispersed in is obtained.

In the first aspect, when the number of forming holes is four, it is as follows.
A mold having first, second, third, and fourth molding holes arranged in a circumferential direction and intersecting radially at 90 ° intervals on the same plane, and a first inserted in each of these molding holes. , Second, third and fourth pressing members are prepared,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdery additive is contained in the first forming hole, and the second, third, and fourth pressing members are second, third, and third. The first pressing member is pushed into the first forming hole while being fixed at the back end of the four forming holes and the second, third, and fourth forming holes are closed, and is accommodated in the first forming hole. The first step of pressing and solidifying the mixed raw material,
Next, the third and fourth pressing members are fixed at the back ends of the third and fourth forming holes, and the first pressing member is further pressed in a state where the second pressing member can be retracted or retracted in advance. By performing a subsequent step of feeding the first mixed hole from the first forming hole to the second forming hole while crushing the mixed material,
Next, with the first, third, and fourth pressing members fixed at the back ends of the first, third, and fourth forming holes and the first, third, and fourth forming holes closed, the second pressing member By pressing the member toward the back of the second forming hole, a pre-stage step of pressing and solidifying the mixed raw material accommodated in the second forming hole is performed,
Next, the first and fourth pressing members are fixed at the back ends of the first and fourth forming holes, and the second pressing member is further pushed in with the third pressing member retreatable or previously retracted. By performing a subsequent process of feeding the mixed raw material from the second forming hole to the third forming hole while crushing,
Next, with the first, second, and fourth pressing members fixed at the back ends of the first, second, and fourth forming holes and the first, second, and fourth forming holes closed, the third pressing By pressing the member toward the back of the third forming hole, a pre-stage step of pressing the mixed raw material accommodated in the third forming hole is performed,
Next, the first and second pressing members are fixed at the back ends of the first and second forming holes, and the third pressing member is further pushed in with the fourth pressing member retreatable or previously retracted. By performing a subsequent process of sending the third mixed hole from the third forming hole to the fourth forming hole while crushing the mixed raw material,
Next, with the first, second, and third pressing members fixed at the back ends of the first, second, and third forming holes and the first, second, and third forming holes closed, the fourth press By pressing the member toward the back of the fourth forming hole, a pre-stage step of pressing the mixed raw material accommodated in the fourth forming hole is performed,
Next, the second and third pressing members are fixed at the back ends of the second and third forming holes, and the fourth pressing member is further pushed in with the first pressing member being retractable or retracted in advance. By performing a subsequent process of sending the mixed raw material from the fourth forming hole to the first forming hole while crushing,
The former process and the latter process for each pressing member are repeated in the above order, and finally the former process is executed in one of the molding holes, whereby the mixed raw material is refined and the additive is uniformly dispersed. Get the body.

  According to this method, it is possible to uniformly refine and disperse the raw material over the entire region of the raw material without taking out the mixed raw material in the middle.

  The structure can be densified by heating and extruding the compression molded body obtained as described above.

  Preferably, the mixed material includes a magnesium alloy chip or granule and silica or silicon powder, and magnesium silicide is solid-phase synthesized by the heat extrusion molding. Thereby, a magnesium compounding material having high strength, low wear and corrosion resistance can be obtained.

  In the present invention, an auxiliary process may be interposed between cycles including the preceding process and the subsequent process.

  According to the present invention, when manufacturing a magnesium composite material, the efficiency of refinement and uniform dispersion of additives can be dramatically improved.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the apparatus used in this embodiment includes a rectangular parallelepiped mold 10. The mold 10 is formed with four straight forming holes 11 to 14 (first to fourth forming holes). These molding holes 11 to 14 have the same cross-sectional shape, preferably have a circular cross-section with the same diameter, and intersect in a radial manner at the center of the mold 10. An intersection of these forming holes 11 to 14 is denoted by reference numeral 19. These forming holes 11 to 14 are arranged on the same plane (on a vertical plane or a horizontal plane) at an angular interval of 90 ° in the circumferential direction in this order.

  In the molding holes 11 to 14, molding pins 21 to 24 (first to fourth pressing members) having substantially the same cross-sectional shape as the molding holes 11 to 14 are slidably inserted so as to move forward and backward. It has become. The forming pins 21 to 24 are moved forward and backward by a hydraulic drive device 30 (drive device) shown in FIG.

  The hydraulic drive device 30 includes a common tank 31 and a pump 32, and for each molding pin 21 to 24, a hydraulic cylinder 33, solenoid valves 34 to 36, a back pressure adjustment valve 37, a pressure sensor 38, and a check valve. 39 is provided. In addition, about the components 33-39, only the thing corresponding to the shaping | molding pin 21 is shown in figure.

  Each hydraulic cylinder 33 has a cylindrical cylinder body 33a, a piston 33b that slides inside the cylinder body 33a, and a rod 33c that is fixed to the piston 33b and protrudes from the cylinder body 33a.

  The tip of the rod 33c of the hydraulic cylinder 33 is connected to the rear ends of the corresponding forming pins 21-24.

  In the hydraulic cylinder 33, the chamber 33x located on the rear side of the piston 33b is connected to a common pump 32 via a solenoid valve. This solenoid valve 34 is a two-port position switching valve. In the off position, the built-in check valve 34a prevents the flow of pressurized oil from the pump 32 to the chamber 33x, and in the on position, the pressurized oil flows. It comes to allow. The solenoid valve 34 and the pump 32 are main components of the pressurized oil supply means.

  A check valve 39 is interposed between the solenoid valve 34 and the pump 32, and the check valve 39 allows a flow from the pump 32 to the chamber 33x and prevents a reverse flow. It has become.

  The chamber 33x is connected to a common tank 31 via a solenoid valve 35. The solenoid valve 35 is a two-port position switching valve. In the off position, the built-in check valve 35a prevents the oil from flowing from the chamber 33x to the tank 31 and allows the oil to flow in the on position. It has become.

  A back pressure adjustment valve 37 is interposed between the solenoid valve 35 and the tank 31. The back pressure adjusting valve 37 adjusts the back pressure (the internal pressure of the chamber 33x) when the forming pins 21 to 24 are retracted. The solenoid valve 35 and the back pressure adjusting valve 37 are main components of the escape means.

  The pressure in the chamber 33x is monitored by a pressure sensor 38, and the drive of the pump 32 is controlled by the pressure detected by the pressure sensor 38. .

  In the hydraulic cylinder 33, the chamber 33 y located on the front side of the piston 33 b is connected to a common tank 31 via a solenoid valve 36. The solenoid valve 36 is a two-port position switching valve. In the off position, the built-in check valve 36a prevents the oil from flowing from the chamber 33y to the tank 31 and allows the oil to flow in the on position. It has become.

  BMA (bulk mechanical alloying) is performed at room temperature in the atmosphere using the apparatus configured as described above. The raw material M used is, for example, a strip-shaped chip of a magnesium alloy AZ31 (magnesium-based alloy containing 3% by weight of Al and 1% by weight of Zn) of about 0.5 mm to 5 mm, as described in the section of the prior art. Alternatively, a granular material is used as a base material, and to this base material, 2 to 10% by weight of an additive made of silicon or silica powder having a particle size of 1 to 50 μm, which is much smaller than the base material (% by weight based on the mixed raw material), Further, a small amount of oleic acid (binder) is added and premixed. Since the silicon or silica powder is much smaller than the magnesium alloy chip, this premixing causes the silicon or silica powder to be coated on the magnesium alloy chip.

  First, as shown in FIGS. 1 and 3A, the raw material M is loaded into the molding hole 11 with the molding pin 21 removed. At this time, the molding pins 22 to 24 are in the forward positions, that is, the positions where the front ends of the molding pins 22 coincide with the rear ends of the molding holes 12 to 14 adjacent to the intersecting portion 19. Since the solenoid valves 34 to 36 corresponding to the molding pins 22 to 24 are all off, the hydraulic cylinder 33 is in a hydraulic lock state. As a result, the molding pins 22 to 24 are restrained in a state in which they cannot be retracted and are substantially fixed. Is in a state.

  After loading the raw material M, the molding pin 21 is inserted into the molding hole 11 and connected to the hydraulic cylinder 33, and then the following sequence control is started by a control unit (not shown).

  First, the pre-stage process is performed on the forming pin 21. More specifically, by turning on only the solenoid valves 34 and 36 corresponding to the molding pin 21, pressurized oil is supplied to the hydraulic cylinder 33, and the molding pin 21 is pushed in as shown in FIG. At this time, since the molding pins 22 to 24 are fixed, the raw material M is pressed into the molding hole 11 without going to the molding holes 12 to 14 and becomes a cylindrical block. This lump has a predetermined strength but is relatively brittle. At the time of this compaction, the drive of the pump 32 is controlled based on the detection signal from the pressure sensor 38 so that the oil pressure from the pump 32 becomes the set pressure. This compacted state is maintained for a short time, for example, about 2 seconds.

  Next, a subsequent process is performed on the forming pin 21. More specifically, the drive of the pump 32 is controlled based on the detection signal from the pressure sensor 38 so that the oil pressure from the pump 32 becomes a set pressure higher than that in the preceding step. As a result, the hydraulic cylinder 33 pushes the forming pin 21 further. At this time, the solenoid 35 corresponding to the molding pin 22 is turned on so that the oil from the chamber 33x of the corresponding hydraulic cylinder 33 is released. Thereby, the forming pin 22 can be retracted. As a result, as shown in FIGS. 3B and 3C, the molding pin 21 is pushed to the advanced position, and the material M is forced to flow from the molding hole 11 to the molding hole 12 through the intersection 19. And is crushed in this process.

  In the subsequent step, the forming pin 22 is pushed back by the raw material M that has flowed. The back pressure adjusting valve 37 corresponding to the forming pin 22 sets a back pressure (1/10 or less) that is far smaller than the set pressure in the subsequent process. As a result, the forming pin 22 is pushed back by the raw material M, but the resistance corresponding to the back pressure works and can be moved backward stably.

  When the front end of the forming pin 21 reaches the back end of the forming hole 21 and is detected by the position sensor, the latter stage process is completed. That is, the solenoid valves 34 and 36 corresponding to the molding pin 21 are switched off, and the molding pin 21 is in a fixed state.

  It is preferable to perform the former stage process and the latter stage process of FIGS. 3A to 3C continuously. That is, the molding pin 22 is switched from the fixed state to the retractable state while the molding pin 21 is kept pressed. The same applies hereinafter.

  Next, the same pre-stage process as that of the molding pin 21 is performed on the molding pin 22. More specifically, the solenoid valves 34 and 36 corresponding to the molding pin 22 are turned on while the molding pins 21, 23 and 24 are restrained and fixed substantially at the forward positions, and the corresponding hydraulic cylinders 33 are used to turn on the solenoid valves 34 and 36. As shown in D), the molding pin 22 is pressed and pushed. Thereby, the raw material M is pressed and hardened.

  Next, a subsequent process similar to that for the molding pin 21 is performed on the molding pin 22. More specifically, the solenoid valve 35 corresponding to the molding pin 23 is turned on so as to be retractable, and the molding pin 22 is pushed in by increasing the pressure applied to the molding pin 22. The forming pins 21 and 24 are kept fixed. As a result, the forming pin 22 is pushed to the advanced position as shown in FIGS. 3E and 3F, and the raw material M is pushed in the process of moving from the forming hole 12 to the forming hole 13 through the intersection 19. Collapsed. The forming pin 23 is pushed by the raw material M and moves backward.

  Next, the same pre-stage process as that of the molding pin 21 is performed on the molding pin 23. More specifically, as shown in FIG. 3G, the raw material M is pressed and pressed by pressing the molding pin 23 while keeping the molding pins 21, 22, and 24 in a fixed state.

  Next, the subsequent process similar to the case of the molding pin 21 is performed on the molding pin 23. More specifically, by making the molding pin 24 retractable and pressurizing the molding pin 23, the molding pin 23 is pushed to the advanced position as shown in FIGS. Is crushed in the process of moving from the forming hole 13 to the forming hole 14 via the intersection 19. The molding pin 24 is pushed back by the raw material M.

  Next, the same pre-stage process as that for the molding pin 21 is performed on the molding pin 24. More specifically, as shown in FIG. 3 (J), the raw material M is consolidated by pressing the molding pin 24 while keeping the molding pins 21, 22, and 23 in a fixed state.

  Next, a subsequent process similar to the case of the molding pin 21 is performed on the molding pin 24. More specifically, by making the molding pin 21 retreatable and pressurizing the molding pin 24, the molding pin 24 is pushed to the forward position as shown in FIGS. 3 (K) and 3 (L), and the raw material M Is crushed in the process of moving from the molding hole 14 to the molding hole 11 through the intersection 19. The forming pin 21 is pushed back by the raw material M.

  The steps of FIGS. 3A to 3L are repeated a plurality of cycles to form a compression molded body by pressing, that is, any one of FIGS. 3A, 3D, 3G, and 3J. At the stage where the previous step is completed, the compression molded body is taken out. For example, in the case of completion at the stage of FIG. 3A, the molding pin 21 is pulled out, the molding pin 23 is advanced so as to pass through the intersection 19, and the compression molded body is pushed out from the molding hole 11.

  Since the raw material M is once compacted as described above and is crushed by receiving a large shearing force and frictional force over the entire cross-sectional area in the process of passing through the intersecting portion 19, the material M is refined, that is, a magnesium alloy. The chip and the powder of silica, silicon, etc. can be made finer and uniformly dispersed.

  In the first embodiment, the shearing force acting on the raw material M acts at a position connecting the upper right corner to the lower left corner of the intersection 19 in the process shown in FIGS. 3 (A) to 3 (C). . The upper right corner of the raw material M flows around the inside and the lower left corner flows around the outer periphery. The outer peripheral portion of the raw material M becomes the inner peripheral side in the following processes of FIGS. 3D to 3F, and becomes the outer peripheral side again in the processes of FIGS. 3G to 3I. It becomes the inner circumference side in the process of FIG. Thus, by repeating the inner circumference and the outer circumference alternately, it is possible to disperse more uniformly.

  Next, another embodiment of the present invention will be described. In these embodiments, components corresponding to the preceding embodiments are assigned the same reference numerals and detailed description thereof is omitted.

  In the second embodiment of the present invention shown in FIG. 4, an apparatus similar to that of the first embodiment is used, but the operation of the forming pin is slightly different. In the previous step of pressing the material M by pressing the forming pin, the forming pin facing 180 ° is advanced to the crossing portion 19 and is restrained (set to a fixed state). For example, when pressurizing the molding pin 21, the molding pin 23 is advanced to the crossing portion 19 and is positioned and fixed at the back end of the molding hole 11. In this case, the forming pins 22 and 24 may be fixed or free. In this case, in the subsequent step, it is necessary to move the molding pin 21 forward after the molding pin 23 is retracted to the far end of the molding hole 13. The same applies to the pressing process of the molding pins 22, 23, 24.

  Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the same apparatus as that of the first embodiment is used. In the former stage of pressing the raw material M by pressing the forming pins, the intersecting portion 19 is closed with the forming pins separated by 90 °. For example, when the molding pin 21 is pressurized, the intersection 19 is closed with one of the molding pins 22, 24, preferably the molding pin 22 of the molding hole 12 into which the raw material flows next. Although it is preferable that the forming pin 22 that blocks the intersecting portion 19 is in a fixed state, it may be free. Further, the other forming pins 23 and 24 facing the intersecting portion 19 may be fixed or free. Also in this case, in the subsequent step, it is necessary to move the molding pin 21 forward after the molding pin 22 is retracted to the far end of the molding hole 12 to be in a retractable state or a free state. The same applies to the pressing process of the molding pins 22, 23, 24.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. In the apparatus of this embodiment, five linear molding holes 11 to 15 having the same sectional shape are formed in the mold 10A, and molding pins 21 to 25 having the same sectional shape are inserted into the molding holes 11 to 15, respectively. The first to fourth molding holes 11 to 14 and the first to fourth molding pins 21 to 24 are the same as those of the first to third embodiments. The fifth forming hole 15 forms a straight line and intersects at 90 ° with a plane on which the first to fourth forming holes 11 to 14 are arranged at the intersecting portion 19.

  When the former process is executed with one molding hole among the molding holes 11 to 15, the other molding hole is fixed by positioning the corresponding molding pin at the back end of the molding hole as in the first embodiment. Block by. Note that other forming holes may be closed in the same manner as in the second and third embodiments. In the subsequent process in the molding holes 11 to 14, only the fifth molding pin 25 is brought into a retractable state or a free state, and the raw material M is moved into the fifth molding hole 15. Thereafter, the fifth forming pin 25 is pressurized to harden the raw material M.

  Next, the fifth molding pin 25 is further pressurized and poured into one of the molding holes 11 to 24 while the material M is crushed. Thus, in the fourth embodiment, the raw material M is compacted and crushed in the order of the first, fifth, second, fifth, third, fifth, fourth and fifth forming holes. It is. Therefore, ten times of compaction and crushing are performed in one cycle.

  In the fourth embodiment, the raw material M may be pressed and crushed only in the fifth forming hole 15. In this case, in the molding holes 11 to 14, the raw materials flow in order at the time of crushing. However, the molding pins 21 to 24 are moved forward to return the raw material to the fifth molding hole 15 without pressing and crushing. In such a method, a large load can be applied only to the fifth molding pin 25 using a large press machine or the like. In this case, it is preferable to extend the forming hole 15 upward from the intersection 19.

  Moreover, in the said 4th Embodiment, you may make it perform the compression and the crushing of the raw material M only by the molding holes 11-14. In this case, the raw material flows into the molding hole 15 when it is crushed. However, the raw material is returned to the molding holes 11 to 14 in order by advancing the molding pin 25 without being pressed and crushed. In this case, it is preferable to extend the forming hole 15 downward from the intersection 19.

  Furthermore, in the said 4th Embodiment, you may use the 5th shaping | molding pin 25 only as a receiving body at the time of the compaction of the raw material M. FIG. That is, only when the raw material M is pressed and hardened in any one of the forming holes 11 to 14, the intersection 19 is closed in the same manner as in FIG.

  Next, a fifth embodiment of the present invention will be described with reference to FIG. In the apparatus of this embodiment, in the mold 10B, three molding holes 11 to 13 (first to third molding holes) are formed on a horizontal plane (on the same surface), and a molding pin 21 is formed in the molding holes 11 to 13. ~ 23 are inserted. The third forming hole 13 is separated from the first forming hole 11 by 90 ° and is separated from the second forming hole 12 by 180 °. Since the basic operation of the forming pins 21 to 23 is similar to that of the first embodiment, it will not be described in detail. However, as shown in FIGS. The raw material M is poured into the second forming hole 12 by pressing, and then the raw material M is pressed and compressed in the second forming hole 12 as shown in FIGS. The raw material M is returned to the first molding hole 11, and then the raw material M is pressed and collapsed in the first molding hole 11 as shown in FIGS. 7 (G) to (I). Next, as shown in FIGS. 7 (J) to 7 (L), the raw material M is pressed and solidified in the third forming hole 13, and then the raw material M is returned to the first forming hole 11. The cycle shown in FIGS. 7A to 7L is executed a plurality of times. In addition, how to close the forming hole in the pressing step of the raw material M may be the same as in FIGS.

  In the fifth embodiment, the raw material M may be pressed and crushed only in the first forming hole 11. In this case, the raw material flows in order in the forming holes 12 and 13 during the crushing, but the forming pins 22 and 23 are advanced to return the raw material to the forming hole 11 without pressing and crushing. In such a configuration, a large load can be applied only to the first molding pin 21 using a large press machine or the like. In this case, it is preferable to extend the first forming hole 11 upward from the intersecting portion 19.

  Further, in the fifth embodiment, the raw material M may be pressed and crushed only by the molding holes 12 and 13. In this case, the raw material flows into the forming hole 11 when it is crushed, but the material is alternately returned to the forming holes 12 and 13 by advancing the forming pin 21 without being pressed and crushed. In this case, it is preferable to extend the first forming hole 11 downward from the intersecting portion 19.

  Next, a sixth embodiment of the present invention will be described with reference to FIG. In the apparatus of this embodiment, two molding holes 11 to 12 (first and second molding holes) are formed in the mold 10C, and molding pins 21 and 22 (first and second molding holes) are formed in the molding holes 11 and 12, respectively. Molding pin) is inserted. Although the basic operation of the forming pins 21 and 22 is similar to that of the first embodiment and will not be described in detail, as shown in FIGS. 8 (A) to (C), the material is pressed and pressed in the first forming hole 11. The material M is poured into the second forming hole 12 by crushing, and then, as shown in FIGS. 8 (D) to (F), the material M is squeezed and compressed in the second forming hole 12 to perform the first crushing. The raw material M is returned to the molding hole 11. One cycle shown in FIGS. 8A to 8F is executed a plurality of times.

  In the embodiment of FIG. 8, since the inner periphery side and the outer periphery side are constant when the shearing force is applied and the material is crushed, the pressed raw material M is taken out every time it is repeated several times and rotated 90 ° or 180 °. More preferably, the same mold hole is loaded again.

  For example, three or six forming holes can be formed along the X, Y, and Z axes orthogonal to each other.

In all the above-described embodiments, the compression molded body having desired fineness and uniform dispersion is preliminarily heated in the solid phase temperature region in the same manner as the above-described conventional technique, and then warm extrusion molding is performed. For example, machining with plastic deformation is performed. The preheating is performed at a temperature of 350 ° C. or higher at which the magnesium crystal grains can be reliably bonded and at a temperature lower than 520 ° C. which is lower than the melting point of magnesium and can suppress the coarsening of the magnesium crystal grains. Due to the heat generated by the preliminary heating and the subsequent plastic deformation, Mg ₂ Si is generated in the magnesium alloy.

Based on 1st Embodiment, it experimented on the following conditions.
(1) The magnesium alloy tip used is a commercially available AZ31 tip, and the size is as follows: Minimum 0.5 mm, Maximum 3 mm, Average 1.5 mm
(2) The silica powder used is also commercially available, and its size is as follows.
Minimum 4μm, maximum 63μm, average 22μm
(3) The addition amount of silica is 2% by weight and 4% by weight in the mixed raw material.
(4) A small amount of oleic acid is added to the mixed raw material and mixed for 15 minutes on a rocking mill. The amount of oleic acid added is 0.5% by weight when the mixed raw material is 100% by weight.
(5) The number of machining cycles is 20 and 40.
(6) In the machining cycle, the hydraulic pressure in the preceding step is 340 Kg / cm ² , and the pressing force applied to the raw material is 4.4 tons.
(7) In the machining cycle, the hydraulic pressure in the subsequent process is 400 kg / cm ² , and the crushing force applied to the raw material is 5.2 tons.
(8) The obtained compression molded body is a cylindrical body having a diameter of 35 mm and a length of 80 mm.
(9) The compression-molded body is preheated, heated to 460 ° C. in 10 minutes, held for 5 minutes, and then extruded.
(10) The extrusion process is performed at an extrusion ratio of 37 using an extrusion die heated to 400 ° C. in a nitrogen gas atmosphere. At this time, the material temperature temporarily rises due to heat generated by plastic deformation. However, the melting point of magnesium is sufficiently lower than 620 ° C.

  When the structure of the molded product obtained by the above extrusion processing was confirmed by micrographs, the crystal grain size of the magnesium alloy was approximately 10 to 20 μm as shown in FIGS. 9 (A) to 9 (D). Satisfactory miniaturization was obtained. Further, as a result of X-ray diffraction of the molded product, it is clear that silica is not detected and the solid phase synthesis of magnesium silicide is completed at both processing cycles of 20 and 40. .

上記表において、「０．２％耐力」，「引張強度」，「伸び」に関する引張りデータは、２本の成形品の平均値であり、ＨＶ硬度は、５点の平均値である。 As a result of performing various strength tests on the molded article, the results shown in Table 1 below were obtained.

In the above table, the tensile data relating to “0.2% proof stress”, “tensile strength”, and “elongation” are average values of two molded products, and HV hardness is an average value of five points.

  Comparative Example (1) is a test result of a molded article obtained by the same raw material and processing as in the above experimental example with 0% by weight of silica. It is a test result about what extruded the compounding material obtained by the processing cycle (refer FIG. 11) described in the column of. In Comparative Example (2), the number of machining cycles is 40 times and 80 times.

  As apparent from Table 1 above, in the experimental example based on the present invention, a higher strength is obtained than in the comparative example (1) and the number of processing cycles is smaller than that in the comparative example (2). ) Higher strength is obtained.

  Next, another experimental example based on the first embodiment will be described. In this experimental example, 96 parts by weight of an average 3 mm magnesium alloy AZ31 chip, 4 parts by weight of 4 μm average silica, and 0.5 parts by weight of a small amount of oleic acid were used as a mixed raw material. . FIG. 10 (A) shows a micrograph of the structure after hot pressing the compression-molded body obtained by compaction and crushing in 20 processing cycles. As a comparative example, FIG. 10B shows a micrograph of the structure after hot pressing a compression-molded body obtained from the same raw material by the conventional technique (see FIG. 11) under the same conditions. In the comparative example, the processing cycle of compaction and backward extrusion is performed 200 times. From the comparison of FIGS. 10A and 10B, it is clear that the miniaturization and uniform dispersion efficiency of the present invention is extremely high.

The present invention is not limited to the above embodiment, and various forms can be adopted. For example, a magnesium alloy other than AZ31 can be used as the base material, and pure magnesium can also be used.
In addition to silica, silicon powder may be used as an additive.
Further, silicon carbide, carbon, aluminum, zirconium or the like may be added as an additive.

BMA may be performed in an inert gas atmosphere.
In all the above-described embodiments, the forming pin of the forming hole into which the raw material flows when the raw material is crushed is made retractable, and a low back pressure is applied to the back pressure adjusting valve 37. Is not necessary. Also in this case, a back pressure of about several Kg / cm 2 is applied due to the resistance of the hydraulic circuit, so that even if the forming pin is pushed by the raw material, it does not retreat greatly. Further, even if there is almost no resistance when the forming pin is retracted and it is completely free, the retracting stroke can be limited by other means.
The forming pin is pushed backward by the raw material, but may be retracted in advance.
In all the embodiments described above, the mold is fixed, and driving means such as a hydraulic cylinder is provided for each molding pin. However, the mold may be rotated. In this case, only one drive means is required.

  The type of BMA may be one in which a plurality of cylinders are connected to cross each other.

It is an expanded sectional view of the apparatus used for 1st Embodiment of the method of this invention. It is a circuit diagram of the principal part of the hydraulic drive unit attached to the apparatus. (A)-(L) is a schematic sectional drawing explaining the apparatus in order of a process. It is sectional drawing of the apparatus used for 2nd Embodiment of this invention method. It is sectional drawing of the apparatus used for 3rd Embodiment of this invention method. It is sectional drawing of the apparatus used for 4th Embodiment of the method of this invention. (A)-(L) is a schematic sectional drawing explaining 5th Embodiment of this invention method to process order. (A)-(F) are schematic sectional drawings explaining 6th Embodiment of this invention method to process order. It is a microscope picture of the extrusion molding product of the compounding material (silica addition amount 2 weight%, processing cycle 20 times) obtained based on this invention. It is a microscope picture of the extrusion molding product of the compounding material (silica addition amount 2 weight%, processing cycle 40 times) obtained based on this invention. It is a microscope picture of the extrusion molding product of the compounding material (silica addition amount 4 weight%, processing cycle 20 times) obtained based on this invention. It is a microscope picture of the extrusion molding product of the compounding material (silica addition amount 4 weight%, processing cycle 40 times) obtained based on this invention. (A) is the microscope picture of the structure | tissue after hot-pressing the compounding material obtained based on this invention, (B) is the microscope picture of the structure | tissue after hot-pressing the compounding material obtained by the conventional method. is there. (A)-(f) is a schematic sectional drawing explaining the conventional method to process order.

Explanation of symbols

10, 10A, 10B, 10C Molds 11 to 15 First to fifth molding holes 19 Intersections 21 to 25 First to fifth molding pins (pressing members)
M raw material

Claims (9)

  A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdered additive is inserted into the molding hole in a state where the raw material is housed in a mold having a plurality of linear molding holes that intersect with each other. As the pressing member is moved forward and backward, the mixed raw material is pressed and solidified in one forming hole, and further, the pressed mixed raw material is crushed and sent to another forming hole, and this pressing and solidifying is repeated. By this, the manufacturing method of the magnesium composite material characterized by obtaining the compression molded object by which the mixed raw material was refined | miniaturized and the additive was disperse | distributed uniformly. Prepare a mold having a plurality of linear molding holes that intersect and cross each other, and a plurality of pressing members respectively inserted into these molding holes,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdered additive is accommodated in one of the plurality of forming holes, and the flow of the mixed raw material into all other forming holes is prohibited. In the state, by pressing one pressing member inserted into the one molding hole toward the back, a pre-stage step of pressing the mixed raw material in the one molding hole is performed,
Next, in a state where the other pressing member inserted into the other one forming hole can be retracted or retracted in advance, the one pressing member is further pushed inward to push the mixed raw material. Execute a subsequent process of feeding from the one forming hole to the other forming hole while breaking,
By repeating the above-mentioned pre-stage process and post-stage process and finally executing the pre-stage process in any one of the forming holes, a compression molded body in which the mixed raw material is refined and the additive is uniformly dispersed is obtained. A method for producing a magnesium composite material. Prepare a mold having a plurality of linear molding holes that intersect and cross each other, and a plurality of pressing members respectively inserted into these molding holes,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdered additive is accommodated in one of the plurality of forming holes, and the flow of the mixed raw material into all other forming holes is prohibited. In the state, by pressing one pressing member inserted into the one molding hole toward the back, a pre-stage step of pressing the mixed raw material in the one molding hole is performed,
Next, in a state where the other pressing member inserted into the other one forming hole can be retracted or retracted in advance, the one pressing member is further pushed inward to push the mixed raw material. Execute the subsequent process of feeding from the one forming hole to the other forming hole while breaking,
Next, by the pressing of the pressing member inserted into the other forming hole, the preceding step involving the compaction of the raw material fed into the other forming hole, and the subsequent step involving the crushing of the mixed material, Run
By repeating the preceding process and the succeeding process in a predetermined order for the plurality of pressing members, and finally executing the preceding process in one of the forming holes, the mixed raw material is refined and the additive is uniformly dispersed. A method for producing a magnesium composite material, characterized in that a compressed compact is obtained. Prepare a mold having a plurality of linear forming holes that intersect and cross each other, and a plurality of pressing members respectively inserted into these forming holes,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdery additive is contained in one selected forming hole, and the raw material is not allowed to flow into all other forming holes. The first step of pressing the one of the pressing members inserted into the selected molding hole toward the back to compress the mixed raw material in the selected molding hole is performed,
Next, in a state where the other one forming pin inserted into the other one forming hole can be retracted or has been retracted in advance, the selected forming pin is further pushed into the back, thereby mixing the raw material. Execute the subsequent process of feeding from the selected molding hole to the other molding hole while crushing,
Next, a return step of returning the mixed raw material of the other forming hole to the selected forming hole by pressing with a pressing member inserted into the other forming hole,
The above process is repeated, and finally the preceding process is executed in the selected molding hole to obtain a compression molded body in which the mixed raw material is refined and the additive is uniformly dispersed. Manufacturing method of magnesium composite material.   The manufacturing method according to claim 1, wherein the forming holes intersect with each other at an angle of approximately 90 °. Preparing a mold having linear first and second molding holes that intersect and cross each other at approximately 90 °, and first and second pressing members respectively inserted into the first and second molding holes;
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdery additive is contained in the first forming hole, and the second pressing member is fixed at the back end of the second forming hole. The second forming hole is closed by this, and in this state, the first pressing member is pushed toward the back of the first forming hole, thereby executing a pre-stage step of pressing and solidifying the mixed raw material accommodated in the first forming hole,
Next, in a state in which the second pressing member can be retracted or retracted in advance, the first pressing member is further pushed into the back so that the mixed raw material is crushed and the second molding is performed from the first forming hole. Execute the latter stage process to feed into the hole,
Next, the first pressing member is fixed at the back end of the first forming hole to close the first forming hole, and in this state, the second pressing member is pushed toward the back of the second forming hole, Performing a pre-stage step of pressing and solidifying the mixed raw material accommodated in the second forming hole;
Next, in a state where the first pressing member can be retracted or retracted in advance, the second pressing member is further pushed into the back, so that the first raw material is pressed from the second forming hole while collapsing the mixed material. Execute the latter stage process to feed into the hole,
The above pre-stage process and post-stage process are alternately and repeatedly executed for the first and second pressing members, and finally the pre-stage process is executed in any one of the forming holes, whereby the mixed raw material is refined and the additive is uniform. A method for producing a magnesium composite material, comprising: obtaining a compression molded body of a mixed raw material dispersed in the material. A mold having first, second, third, and fourth molding holes arranged in a circumferential direction and intersecting radially at intervals of 90 ° on the same plane, and a first inserted into each of these molding holes. , Second, third and fourth pressing members are prepared,
A mixed raw material containing magnesium or a magnesium alloy chip or granule and a powdery additive is contained in the first forming hole, and the second, third, and fourth pressing members are second, third, and third. The first pressing member is pushed into the first forming hole while being fixed at the back end of the four forming holes and the second, third, and fourth forming holes are closed, and is accommodated in the first forming hole. The first step of pressing and solidifying the mixed raw material,
Next, the third and fourth pressing members are fixed at the back ends of the third and fourth forming holes, and the first pressing member is further pressed in a state where the second pressing member can be retracted or retracted in advance. By performing a subsequent step of feeding the first mixed hole from the first forming hole to the second forming hole while crushing the mixed material,
Next, with the first, third, and fourth pressing members fixed at the back ends of the first, third, and fourth forming holes and the first, third, and fourth forming holes closed, the second pressing member By pressing the member toward the back of the second forming hole, a pre-stage step of pressing and solidifying the mixed raw material accommodated in the second forming hole is performed,
Next, the first and fourth pressing members are fixed at the back ends of the first and fourth forming holes, and the second pressing member is further pushed in with the third pressing member retreatable or previously retracted. By performing a subsequent process of feeding the mixed raw material from the second forming hole to the third forming hole while crushing,
Next, with the first, second, and fourth pressing members fixed at the back ends of the first, second, and fourth forming holes and the first, second, and fourth forming holes closed, the third pressing By pressing the member toward the back of the third forming hole, a pre-stage step of pressing the mixed raw material accommodated in the third forming hole is performed,
Next, the first and second pressing members are fixed at the back ends of the first and second forming holes, and the third pressing member is further pushed in with the fourth pressing member retreatable or previously retracted. By performing a subsequent process of sending the third mixed hole from the third forming hole to the fourth forming hole while crushing the mixed raw material,
Next, with the first, second, and third pressing members fixed at the back ends of the first, second, and third forming holes and the first, second, and third forming holes closed, the fourth press By pressing the member toward the back of the fourth forming hole, a pre-stage step of pressing the mixed raw material accommodated in the fourth forming hole is performed,
Next, the second and third pressing members are fixed at the back ends of the second and third forming holes, and the fourth pressing member is further pushed in with the first pressing member being retractable or retracted in advance. By performing a subsequent process of sending the mixed raw material from the fourth forming hole to the first forming hole while crushing,
The former process and the latter process for each pressing member are repeated in the above order, and finally the former process is executed in one of the molding holes, whereby the mixed raw material is refined and the additive is uniformly dispersed. A method for producing a magnesium composite material, comprising obtaining a body.   The method for producing a magnesium composite material according to any one of claims 1 to 7, wherein the compression-molded body is heated and extruded.   9. The method for producing a magnesium composite material according to claim 8, wherein the mixed material includes chips or granules of magnesium alloy and silica or silicon powder, and magnesium silicide is solid-phase synthesized by the heat extrusion molding. .

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