118 results about "Powder injection molding" patented technology

The invention belongs to the field of powder injection molding, and relates to a method for preparing a high-strength and high-toughness 6-series aluminum alloy through metal powder injection molding, which comprises the following steps: step 1, mixing 6-series aluminum alloy powder and a binder in a mixing mill to obtain a feed; 2, the feed is subjected to injection molding to form a green body; 3, the green body is subjected to catalytic degreasing through oxalic acid, and a brown blank is obtained; step 4, sintering the palm blank by using a vacuum degreasing sintering furnace and adopting inert gas protection negative pressure; and 5, the sintered sample is subjected to heat treatment, and a 6-series aluminum alloy product is obtained. The prepared 6-series aluminum alloy contains nano MgAl2O4 particles, the nano MgAl2O4 particles are distributed in a net shape at the grain boundary, the density of the 6-series aluminum alloy is larger than 99%, and the tensile strength of the 6-series aluminum alloy is larger than 350 Mpa.

The invention relates to a preparation method of Cr alloyed low-density steel, powder and complex parts, and the Cr alloyed low-density steel is characterized by comprising the following components in percentage by weight: 13% < = Mn < = 43%, 9% < = Al < = 15%, 0.5% < = C < = 1.5%, 4% < = Cr < = 6% and the balance of Fe; on the basis, other elements can be added for strengthening. The preparation method of the complex part comprises the following steps: preparing the powder of the low-density steel through smelting, and preparing the complex part through a powder injection molding process. The sintered blank prepared through the method is of an austenite and ferrite dual-phase structure, a small amount of k-type carbide is contained on the basis of the austenite-based dual-phase structure, the sintering density is smaller than or equal to 6.4 g / cm < 3 >, the yield strength is larger than or equal to 900 MPa, and the ductility is larger than or equal to 5%.

The invention discloses a method for preparing a large part by using a metal powder injection molding process, belongs to the technical field of large part processing, and aims to solve the technical problem that the strength of the large part prepared by metal powder injection molding in the prior art needs to be further improved. The method comprises the following steps that a reinforcing agent, paraffin and acetone are added into a reaction kettle to be stirred, the temperature of the reaction kettle is increased to 40-50 DEG C, stirring is conducted till a system is dissolved, reinforced modified liquid is obtained, metal powder is added into a high-speed mixer to be heated, and when the temperature of the metal powder reaches 100-110 DEG C, the reinforced modified liquid is slowly added into the high-speed mixer; according to the method, the ultimate tensile strength, the yield strength, the ductility and the hardness performance of an injection part are effectively improved by preparing the modified metal powder with the high flowing property and combining the modified metal powder with the bonding auxiliary agent and optimizing the injection condition and the degreasing roasting condition.

The invention provides a binder system for beryllium-titanium alloy powder injection molding and application, and relates to the technical field of metal powder injection molding. The adhesive system consists of the following components in percentage by weight: 76 to 84 percent of polyformaldehyde, 7 to 9 percent of high-density polyethylene, 5 to 7 percent of ethylene-vinyl acetate copolymer, 3 to 5 percent of paraffin, 0.1 to 0.5 percent of stearic acid, 0.1 to 1.5 percent of polyethylene glycol and 0.1 to 1 percent of BASF antioxidant. The feed preparation method based on the system comprises the steps of powder pretreatment, binder preparation, banburying mixing and cooling granulation, and uniform coating and dispersion of beryllium-titanium powder can be achieved. According to the system, the problems that in beryllium-titanium alloy injection molding, powder is prone to oxidation, poor in fluidity and low in size precision are solved, the viscosity of the prepared feed at 180 DEG C is 88-101 Pa.S, and the oxygen content is smaller than or equal to 0.24 wt%; the relative density of a finished product is larger than or equal to 96.5%, the size precision is + / -1% / in-+ / -2% / in, and the method is suitable for industrial production of beryllium-titanium alloy complex parts in the fields of spaceflight and nuclear energy.

The invention relates to the field of powder injection molding materials, in particular to a metal injection molding aluminum-containing stainless steel material and a preparation technology, and the stainless steel material comprises the following components in percentage by mass: 6-8 wt% of Ni, 15-18 wt% of Cr, 0.5-2.5 wt% of Al and 1t of C; 0.2 wt%, and the O content is lt; the low-carbon and low-oxygen metal powder is obtained through vacuum gas atomization, the metal powder is formed through the injection molding process and then is degreased through organic oxalic acid, hydrogen is adopted in the whole process of the thermal degreasing stage, and the low-carbon and low-oxygen metal powder is obtained through the gas atomization powder preparation process, so that the low-carbon and low-oxygen metal powder is obtained. The aluminum-containing stainless steel material which is low in carbon, low in oxygen, high in compactness, high in strength, high in corrosion resistance and high in high-temperature creep resistance is obtained through the processes of heat treatment, rapid heating and heat preservation, and the C content of the stainless steel material prepared through the preparation process is 1t after heat treatment; 0.2 wt%, oxygen content lt; the 0.2 wt% structure is compact, the sintering density is high, and the normal-temperature and high-temperature mechanical strength is higher than that of conventional materials such as 304L, 316L and 17-4PH.

The present invention discloses a method for preparing copper alloy by metal powder injection molding and a high-strength and high-conductivity copper alloy, belonging to the technical field of powder metallurgy, including: mixing copper alloy and pure titanium powder to obtain mixed powder or pre-alloyed powder; mixing the mixed powder or pre-alloyed powder with a binder, and extruding after kneading to make granular feedstock; injecting the granular feedstock into a mold to form a green body; performing catalytic debinding on the green body; performing two-stage sintering on the green body after catalytic debinding to obtain a sintered part; and performing post-treatment on the sintered part to obtain the final alloy. This method can ensure that the finally sintered copper alloy has a high density and performance level.

The invention relates to a moulding tool assembly (5) for powder injection moulding of a component (1), a method for manufacturing a component (1), and a component obtainable by the method wherein the moulding tool assembly (5) comprises: i) at least a first and a second tool part (21, 22, 22a, 22b, 23, 24), the first tool part and the second tool part are arranged to define a mold cavity (25) for forming a component (1); ii) an inlet channel (30) for filling the mold cavity (25) with a molding material (3), the inlet channel (30) extending through an opening in the first tool part (21) to the mold cavity (25) and comprising an outlet end (33) having an outlet opening (34) for discharging the molding material (3) from the inlet channel (30) into the mold cavity (25); iii) a core pin (40) extending through an opening in the second tool portion (22, 22a, 22b), the core pin (40) being movable along a horizontal axis between a rear end position and a front end position, the horizontal axis extending through a center of the core pin (40) and a center of the inlet channel (30), the core pin (40) comprising an end portion (41), the end portion (41) has an end surface (42) facing the outlet opening (34); the core pin (40) is configured to seal the opening in the second tool portion (22, 22a, 22b) with the end portion (41) thereof when the core pin (40) is positioned in a rear end position; and wherein, when the core pin (40) is in its front end position, the core pin (40) is positioned such that the molding material (3) entering the molding cavity (25) impinges on the core pin (40); and iv) a power source (43) configured to maintain the core pin (40) in its front end position until a predetermined pressure threshold is exceeded during filling of the mold cavity (25), while moving the core pin (40) to the rear end position; or v) a power source (43) configured to hold the core pin (40) in its front end position for a predetermined time and to move the core pin (40) to the rear end position after the predetermined time.

The invention relates to the field of powder injection molding materials, in particular to an NbC particle reinforced ultra-high-strength steel composite material and a molding process thereof, the composite material is prepared by mixing NbC powder and ultra-high-strength steel powder, the volume ratio of the NbC powder to the ultra-high-strength steel powder is 1: 19-3: 17, namely, the volume fraction of NbC is 5%-15%. The D50 of the NbC powder is 1.0 [mu] m + / -0.5 [mu] m. The forming process comprises the steps of raw material preparation, mixing, banburying and granulation, injection molding, degreasing, sintering and heat treatment. The NbC particles in a specific proportion are added into an ultrahigh-strength steel matrix through a metal injection molding process, so that the wear resistance of the material is remarkably improved, meanwhile, the high-strength characteristic is kept, and the dual requirements of high strength and high wear resistance are met.

The utility model discloses a water-cooled mold for metal powder injection molding, which comprises a supporting bottom plate, the top of the supporting bottom plate is fixedly connected with a supporting seat, and the top of the supporting seat is fixedly connected with a lower mold seat. Water is injected into a spiral water passing round cavity through a water inlet pipe, cold water is introduced into a lower mold base through the spiral water passing round cavity for preheating, and preheated water enters a heat preservation pipe through a first water drainage pipe and enters a communicating water cavity through a water passing pipe for mold cooling treatment; cooling water in the communicating water cavity is led into the centralized cooling cavity through the vertical water passing round cavities, and water cooling treatment is conducted on a workpiece in the lower die base.

The invention relates to the technical field of powder injection molding control, in particular to a control method and system for powder injection molding based on quantum computation.The method comprises the steps that fitting calculation is conducted on the loading capacity, the powder mass, the powder density, the plastic adding density and the finished product density, intermediate parameters of the proportional relation between plastic and powder are obtained, and a proportionality coefficient is deduced; and the formula calculation precision is improved. The volume ratio is calculated based on the design size and the actual measurement size of the workpiece, the proportion of the adhesive is dynamically corrected, and the process instability caused by proportion imbalance is avoided. And further constructing a quantum circuit comprising a Hadamard door, a revolving door and a full-connection CZ door, performing quantum state sampling on the component proportion, and iteratively optimizing a cost function of density and shrinkage rate in combination with SLSQP and L-BFGS-B algorithms to realize global optimization. Through proportional truncation and normalization correction and verification through preset constraints, the stability of powder injection molding and the consistency of finished products are improved.

The invention relates to the field of powder metallurgy, and discloses a preparation method of a powder injection molded high-strength titanium alloy, which comprises the following steps: S1, titanium alloy powder preparation: preparing titanium alloy powder by adopting a plasma rotating electrode method, and ensuring that the powder comprises the following components in percentage by weight: 5.5-6.85% of Al, 2.95-4.1% of V, 0.3-0.5% of Zr, 0.1-0.4% of Mo and the balance of Ti; according to the invention, the element B is added to form a nano TiB reinforced phase, so that the strength is obviously improved; the tensile strength is greatly improved by combining ultrahigh-pressure sintering with a graded aging process, and the degreasing time is shortened by combining solvent extraction with plasma-assisted thermal degreasing.

This invention discloses a liquid-cooled microchannel powder metallurgy fabrication method, belonging to the field of radiator manufacturing technology. The invention employs a pre-stamping process to prepare copper heat dissipation fins, combined with customized spherical high-purity copper powder and composite polymer bonding particles. A uniform mixture is prepared through segmented high and low temperature and high and low speed stirring. This is then combined with metal powder injection molding, oxalic acid degreasing, nitrogen atmosphere constant temperature anti-oxidation pretreatment, and high-vacuum sintering processes, along with controllable molding and sintering parameters, to fabricate a copper liquid-cooled microchannel radiator. This invention effectively solves the problems of difficult molding of thin-walled pure copper microchannel structures, poor dimensional consistency, and susceptibility to defects and springback. It significantly improves the extrusion of copper materials in microchannel structures, the smoothness of the inner wall, and the overall density, strengthens the bond strength between the fins and the substrate, and eliminates leakage, corrosion, and heat dissipation attenuation under long-term liquid cooling cycles. The product yield is high, and the stability is excellent.

The invention belongs to the technical field of metal material preparation, and discloses a feed formula for a low-oxygen-content titanium alloy FGF (Fibroblast Growth Factor), which consists of 85-92% of titanium alloy powder and 8-15% of a multi-element binder system, the binder comprises a polylactic acid / polycaprolactone blending skeleton capable of being catalytically degraded, a wax component capable of being extracted at low temperature, a compound surfactant and a high-boiling-point plasticizer, and a supported stannous octoate catalyst is introduced. According to the invention, a multi-component binder system consisting of a catalytically degradable polymer skeleton, a wax component capable of being extracted at a low temperature, a compound surfactant and a high-boiling-point plasticizer is constructed, and a two-stage degreasing process is matched, so that the fundamental contradiction between the degreasing efficiency and the material purity in titanium alloy powder injection molding is successfully solved; and a feasible technical path is provided for large-scale manufacturing of high-reliability and high-purity titanium alloy complex components.

The invention relates to the field of ceramic part injection molding, in particular to a ceramic part powder injection molding mold and process based on CIM, and solves the problems that an existing ceramic part injection mold is troublesome in switching and low in production efficiency. The injection molding device comprises a base, an injection molding machine, lantern rings, a front disc, a rear disc, a T-shaped pipe, a thick injection molding head, a straight pipe, a thin injection molding head, a sleeving head, a driving assembly, a sliding frame, a rotating disc cylinder, a lower mold base, an upper mold base, an injection molding opening and a first telescopic part, rotating plates are rotationally connected between the output end of the lower side of the first telescopic part and the two lantern rings, and mold switching assemblies are arranged on the lantern rings; the die switching assembly is used for driving and switching all the lower die bases installed on the rotary disc cylinder in an array mode, the sliding frame is further provided with a linkage assembly, and the linkage assembly is used for driving the sliding frame to slide towards one side when the front disc and the rear disc rotate. According to the device, various molds can be flexibly switched, and efficient injection molding machining production of various ceramic parts is achieved.

The utility model discloses a powder injection molding blank catalytic degreasing device, which belongs to the technical field of catalytic degreasing furnaces and comprises a catalytic degreasing furnace body and a furnace door. According to the powder injection molding blank catalytic degreasing device, a furnace door is closed and drives a second fixing barrel to sleeve a first fixing barrel, the temperature in a catalytic degreasing furnace body is gradually increased, and at the moment, easily-expandable gas in a sealing barrel starts to be heated and expanded, so that a piston circular plate is driven to slide towards the inner side of the catalytic degreasing furnace body; meanwhile, the circular sliding rod abuts against a sliding groove of a spiral sliding groove rod to drive the spiral sliding groove rod to rotate, so that a rotating rod and a driving disc rotate, an arc-shaped anti-skid ring abuts against the inner wall of a circular clamping groove of a second fixing barrel and enters the circular clamping groove, and therefore the furnace door is limited and cannot be opened; therefore, workers can be prevented from being scalded by opening the furnace door when the internal temperature of the catalytic debinding furnace body is not reduced.

The utility model relates to the technical field of injection molding equipment, in particular to metal powder injection molding equipment which comprises a molding cylinder, a molding groove is formed in the molding cylinder, a limiting ring is installed at the position, close to the top end, of the inner wall of the molding groove, an ejection structure is installed in the molding groove, and the ejection structure comprises four sets of limiting cylinders. A mounting ring is mounted on the side surface of the forming cylinder, two sets of electric push rods are mounted at the top end of the mounting ring, and the top ends of the two sets of electric push rods are both mounted to the bottom end of a mounting disc. Through the arrangement of parts such as a limiting barrel, a compression spring, an ejector plate, a mounting ring, an electric push rod, a mounting disc, a feeding barrel, an injection pipe, a motor, a mounting rod, a stirring roller, a scraping plate and a feeding hole, the problems that in the process from material conveying to injection molding of existing injection molding equipment, metal powder is prone to thermal shrinkage and condensation can be effectively solved; the non-uniform or hardening condition is caused during injection molding, so that the injection molding quality is influenced.

The invention relates to the field of powder injection molding materials, in particular to high-strength, high-toughness and high-wear-resistance tool steel and a molding process thereof, and the tool steel comprises the following components in percentage by mass: 1.0-1.6% of C, 0.1-0.6% of Si, less than 1.0% of Mn, less than 1.0% of P, less than 1.0% of S and the balance of Fe. The alloy comprises the following components in percentage by weight: 3.0%-8.0% of Cr, 0.5%-3.0% of Mo, 0.5%-2.0% of V and less than 1% of Zr; 1.0% to 4.0% of Nb; less than 5.0% of Co; ce / La: less than 0.1%; according to the tool steel material, the size of main carbides in the tool steel material is finally smaller than 2 micrometers through the injection molding technology, selection of appropriate alloy elements and content and the appropriate heat treatment technology, and therefore the material has better abrasion resistance and meanwhile has good toughness and high strength.

The invention belongs to the field of powder injection molding materials, and particularly relates to an injection molding additive for 5G optical communication and a preparation method and application thereof. The additive comprises the following raw material components in parts by weight: 80-100 parts of polystyrene; 0.1 to 3 parts of a surfactant; 0.1 to 5 parts of a lubricant; 2-6 parts of glass fiber; 4-8 parts of hollow glass beads; 1-3 parts of a flame retardant; and 0.5-2 parts of an antioxidant. According to the present invention, polystyrene is adopted as the base resin, a variety of functional assistants are added, and the formula is optimized, such that the obtained additive is used in the 5G optical communication injection molding process, such that the uniform powder dispersion can be promoted, the fluidity is good, the processing performance is excellent, and the material strength and the signal transmission efficiency and strength can be improved.

The invention relates to the technical field of injection molding, in particular to a steel alloy powder injection molding method with strength and a high polishing effect. The injection molding method comprises the following steps: preparing a green body from steel alloy powder and TiH2 powder, and sequentially degreasing and sintering the green body to obtain a steel alloy product; the sintering is carried out in a mixed atmosphere of hydrogen and argon, and the temperature is raised to 1250-1400 DEG C at a heating rate of 3-15 DEG C / min during sintering. According to the injection molding method, TiH2 powder is added into high-strength steel powder, the overall compactness of the material is improved, a small amount of Ti element is introduced, and the strength of the material is improved; and meanwhile, by increasing the heating rate of the sintering section and introducing the hydrogen atmosphere in the sintering process, surface layer pores are rapidly closed, and the high-strength steel with the strength and the polishing property is obtained.

The invention discloses an automatic material taking and discharging device of a metal powder injection molding machine, and relates to the technical field of metal injection molding, the automatic material taking and discharging device comprises a motor base, an output shaft of the motor base is connected with a vertical rod, the upper end of the vertical rod is connected with a cross beam, and a hydraulic cylinder is installed on the upper portion of one side of the cross beam; a manipulator is connected to the position, located below the cross beam, of an output shaft of the hydraulic cylinder, the manipulator comprises a shell base, a servo motor is installed on the upper portion of the shell base, the output shaft of the hydraulic cylinder is connected to the upper portion of the servo motor, and a screw is connected to the position, located in the shell base, of the output shaft of the servo motor. According to the automatic material taking and discharging device of the metal powder injection molding machine, the servo motor drives the screw rod and the threaded sleeve to be linked, so that a workpiece is accurately adsorbed by the suction cup, meanwhile, the supporting plate gradually moves towards the bottom of the workpiece in the upward moving process of the threaded sleeve, and finally the bottom of the workpiece is supported; by means of the design, the workpieces are effectively prevented from falling off in the sucking and hoisting processes.

The invention discloses a laser automatic sprue removing device and method in a powder injection molding process, a laser cutter is installed on a sliding block of a vertical module, a conveying module and two conveying rails symmetrically distributed about the conveying module are installed above a machine table, a conveying plate is installed on the conveying rails in a front-back sliding mode, and a laser cutter is installed on a sliding block of the vertical module. A conveying plate is fixed to a sliding block of the conveying module, a blank fixing mold is fixed to the conveying plate, a protection structure used for protection during cutting is installed on the left side of the upper portion of the conveying plate, and a supporting and clamping structure used for supporting and fixing a blank sprue and an air suction piece used for dust collection and cooling are installed in the protection structure; the supporting and clamping structure is arranged in the protection structure, the pouring gate can be clamped and fixed before cutting, the situation that the pouring gate droops due to the weight of the pouring gate in the cutting process is avoided, notch dislocation caused by gravity is effectively prevented, and the cutting quality is improved.

The utility model discloses a continuous internal mixer for powder injection molding feeding, and belongs to the technical field of internal mixers. A continuous internal mixer for powder injection molding feeding comprises a supporting base, and an internal mixing driving part and an internal mixing cylinder box which are respectively mounted above the supporting base, and further comprises a feeding assembly which is fixed right above the internal mixing cylinder box and is used for feeding powder; the discharge port is fixed on one side of the internal mixing cylinder box and is used for discharging the mixed feed; wherein a preheating cavity is formed in the internal mixing cylinder box; according to the internal mixing device, the internal mixing cylinder box, the preheating cavity, the water inlet pipe and the water outlet pipe are matched, so that the internal mixing device can be preheated in advance, a good working environment can be provided when powder and a binder are mixed, the problem of low processing efficiency during mixing is solved, and the service life of the powder and the binder is prolonged. And the mixing uniformity of the powder and the binder is further improved.

The invention relates to a preparation method of an integrally-formed complex cavity part and a liquid cooling plate. According to the method, a material which can be decomposed or dissolved under the acid catalysis condition and / or the action of a specific solvent is adopted to be subjected to injection molding to form a removable insert; then, in a powder injection molding die, wrapping the removable insert with a metal feed to form a composite green body; thirdly, the composite blank is placed in a corresponding acid catalysis atmosphere or a specific solvent, insert removal and catalytic degreasing are synchronously completed, and a degreased blank with a complex cavity is obtained; and finally, sintering and post-processing to obtain a final part. The method is especially suitable for preparing liquid cooling plates containing complex flow channels such as microchannels and pin fins. Integrated net forming of a complex inner cavity structure is achieved, assembly errors and interface thermal resistance caused by split manufacturing are thoroughly avoided, the part density is high, the size precision is good, the heat dissipation performance is excellent, meanwhile, the manufacturing method has the advantages of high efficiency and low cost of the MIM technology, and the manufacturing problem of a high-power device heat dissipation assembly is perfectly solved.

Methods of manufacturing a turbine shroud segment for a gas turbine engine are disclosed. One method involves receiving a turbine shroud segment green part, machining an axial cooling flow passageway in the turbine shroud segment green part, and after the machining of the axial cooling flow passageway, debinding and sintering the machined turbine shroud segment green part. Another method involves receiving a turbine shroud segment green part, machining a textured surface on the radially outer surface of the body to obtain a machined turbine shroud segment green part, and after the machining of the textured surface, debinding and sintering the machined turbine shroud segment green part. Another method involves injecting powder injection molding material into a mold having cavities defining negatives of features forming a textured surface on the radially outer surface of the body, and debinding and sintering the molded turbine shroud segment green part.

The utility model relates to the technical field of metal powder feeding, and discloses a metal powder injection molding feeding machine which comprises a bottom plate, a mixing barrel is installed on the top of the bottom plate, the right side of the mixing barrel is communicated with a discharging pipe, an auger conveyor is installed on the right side of the discharging pipe, and an injection molding machine is installed on the right side of the auger conveyor. According to the screening device, the screening assembly is arranged, a motor is started, a bevel gear A drives two bevel gears B to rotate in the opposite directions, two transverse rods drive two connecting bevel gears to rotate, the two transmission bevel gears move in the opposite directions, and then two vertical rods move in the opposite directions; and a cam drives a concentric-square-shaped frame to move back and forth in the horizontal direction, a pressed block continuously extrudes a triangular pressing block, an abutting rod continuously knocks a screening plate, vibration of the screening plate is achieved, it is guaranteed that metal large-particle powder is screened out in the screening process, and the screening efficiency of the device is improved.

This invention discloses a process for preparing ceramic particle-reinforced steel-based composite materials, belonging to the field of wear-resistant material preparation technology. The method of this invention includes: a powder mixing process, a powder injection molding process, a vacuum debinding process, and a vacuum hot-pressing sintering process. The process scheme is as follows: First, ceramic particles with attached rare earth elements Y and La, iron powder, and an organic binder are added to a ball mill jar and thoroughly mixed using a planetary ball mill. The granulated powder is heated and plasticized, then injected into a mold cavity using a powder injection molding machine. After curing and shaping through processes such as pressure holding, debinding is performed using a vacuum debinding furnace. Finally, the ceramic particle-reinforced steel-based composite material is obtained through vacuum hot-pressing sintering. The method of this invention can prepare metal-based composite materials on a large scale, resulting in a denser microstructure and wear-resistant materials with better resistance to wear, corrosion, and impact.

The invention relates to the field of metal powder injection molding, and discloses an efficient molding method for universal appliance MIM parts. The method comprises the following steps: feed preparation and parameter matching based on digital twin simulation; carrying out self-adaptive injection molding by utilizing a mold with a sensor; based on injection data and online weighing feedback, data-driven degreasing and sintering are executed in the integrated equipment; and finally, continuous optimization is realized through model verification and data closed loop. According to the method, rapid and flexible adaptation of multi-specification parts is achieved through the structure-process mapping database and intelligent simulation, process splitting is broken through real-time sensing and feedback control, fine compensation is carried out on a complex structure by means of a multi-physical field model, and therefore the production efficiency and the size precision are improved, and meanwhile the production cost is reduced. And the process stability and the product consistency are remarkably enhanced, and the effects of efficient forming and high-precision forming of the same-series multi-variety parts are achieved.

This invention provides a directional thermally conductive copper-based diamond composite material and its preparation method, belonging to the technical field of copper-based diamond composite materials. By constructing a "diamond particle size gradient + aluminum nitride / silicon carbide ceramic gradient," combined with multilayer powder injection molding and segmented vacuum hot pressing, the thermal conductivity and thermal expansion in the thickness direction are synergistically controlled: the upper layer of fine-grained diamond and a small amount of aluminum nitride forms a high thermal conductivity layer, the middle layer of medium-grained diamond and a relatively high amount of aluminum nitride acts as a thermal-mechanical buffer, and the lower layer of coarse-grained diamond and silicon carbide improves the expansion matching and sintering stability of the substrate side; sequential injection combined with interval time and thickness ratio control forms a continuous composition gradient and particle intercalation interface during debinding and densification processes, and through two-step heating, three-stage pressure, depressurization and slow cooling, and medium-temperature heat preservation, densification, interfacial reaction and residual stress release are taken into account, so that the copper-based diamond composite material maintains high thermal conductivity while having an adjustable expansion gradient and high structural reliability.

The present invention relates to the technical field of sintering fixtures, and discloses a sintering fixture for metal powder injection molding, which includes a chassis. A fixing sleeve, a plurality of unloading components and a plurality of supporting components are connected to the upper surface of the chassis. Among them, the fixing sleeve is located in the middle of the chassis, and the plurality of unloading components and the plurality of supporting components are circumferentially distributed around the fixing sleeve, and the plurality of unloading components and the plurality of supporting components are arranged in a cross manner. A sliding component is connected inside the fixing sleeve, and a suspension component and a rotating component are connected to the outer wall of the upper end of the sliding component. The lower end of the suspension component is connected with a plurality of shaping components, and the plurality of shaping components are circumferentially distributed around the sliding component. For this sintering fixture for metal powder injection molding, by arranging a plurality of unloading components and supporting components on the chassis, the blanking can be carried out more quickly and accurately after the workpiece is sintered; by arranging the sliding component, it can be adjusted more appropriately in cooperation with the height and angle changes of the unloading components and the supporting components.

The invention discloses a powder injection molding method for improving the performance of maraging steel. The powder injection molding method comprises the following steps that maraging steel powder and a binder are kneaded to prepare feed; the prepared feed is subjected to crushing and granulation; carrying out injection molding on the crushed and granulated feed to obtain a green body; performing catalytic degreasing on the prepared green body; sequentially performing negative pressure degreasing, vacuum internal sintering and sintering on the sample subjected to catalytic degreasing to obtain a sintered part; the obtained sintered part is subjected to solid solution and quenching treatment, and a solid solution part of a full-martensite structure is obtained; the obtained solid solution part is subjected to pre-stretching treatment; and aging treatment is conducted on the pre-stretched sample, and the maraging steel is obtained. According to the present invention, the material is subjected to proper pre-stretching so as to introduce the high-density and uniform dislocation to improve the precipitation of the strengthening phase, such that the comprehensive performance of the material is improved, and the density of the dislocation introduced through the pre-stretching is high so as to appropriately reduce the addition of the noble metals such as Co, Mo and the like so as to easily reduce the cost;