A kind of preparation method of cemented carbide with complicated shape productTechnical field
The present invention relates to hard alloy preparing technical field, particularly relate to a kind of complicated shape hardThe preparation method of alloy product.
Background technology
Hard alloy has high rigidity, high-wearing feature, good chemical stability and heat stability,It is widely used in modern tool material, high-abrasive material, exotic material, resistant material etc..Traditional compression-moulding methods cannot prepare complex-shaped product, and the size and shape of goods is subject toCertain restriction, is susceptible to deformation and dimension overproof.Injection molding technology can manufacture shapeComplicated, dimension precision requirement high, the goods produced in enormous quantities, even density, each to contraction phaseWith similar to hot investment casting, and precision and surface roughness are good, it is not necessary to following process.
The currently used more sintering method of injection moulding hart metal product is vacuum-sintering.ByRelatively low in the density of injection moulding base, the removing of binding agent makes initial porosity when sintering relativelyHeight, therefore vacuum-sintering often cannot obtain densification product, thus affects properties of product.UsePressure sintering method, contributes to hard alloy crystal grain and recombinates and densification when liquid-phase sintering, fromAnd ensure that product quality.
Summary of the invention
It is desirable to provide the preparation method of a kind of cemented carbide with complicated shape product, can makeStandby various cemented carbide with complicated shape products, solve injection forming product by pressure sintering and burnThe shortcomings such as knot densification difficulty, enhance product performance.
It is an object of the invention to use techniques below means to realize.Propose according to the present invention
The preparation method of a kind of cemented carbide with complicated shape product, it comprises the steps:
(1) mixing: cemented carbide powder and binding agent are proportionally weighed, add mixingIn machine, heating is the most mixing；
(2) pelletize: use extrusion device that feeding is extruded into banding, strip, pass through pulverizerPelletize；
(3) injection moulding: the feeding after pelletizing uses injector to inject variously-shapedHard alloy injection base；
(4) defat: remove portion of binder, then heating removing residue the most in a solventBinding agent；
(5) pressure sintering: pressure sintering in sintering furnace, it is thus achieved that densified product.
The purpose of the present invention can also use techniques below measure to realize.
The preparation method of aforesaid a kind of cemented carbide with complicated shape product, described binding agent isParaffin, high density polyethylene (HDPE), polypropylene and the compound binding agent of stearic acid composition.
The preparation method of aforesaid a kind of cemented carbide with complicated shape product, melting temperature is120-180 DEG C, mixing time is 2-6h.
The preparation method of aforesaid a kind of cemented carbide with complicated shape product, injection temperature is160-180 DEG C, injection pressure is 60-80MPa, and mould temperature is about 30 DEG C.
The preparation method of aforesaid a kind of cemented carbide with complicated shape product, solvent degreasing can be selected forOne in trichloro ethylene, chloroform or normal heptane, skimming temp is 45-70 DEG C, defatTime is 5-8h；Thermal debinding uses defat under N2 atmosphere, and skimming temp is 450-500 DEG C.
The preparation method of aforesaid a kind of cemented carbide with complicated shape product, the sintering of pressure sinteringTemperature is 1390-1450 DEG C, and temperature retention time is 60-90min, and pressure is 5-10MPa.
Compared with prior art, the present invention has the following beneficial effect:
(1) using injection molding technology, can prepare complex-shaped product, raw material utilizesRate is high, is suitable for producing in enormous quantities；
(2) use pressure sintering method, solve asking of injection forming product densification difficultyTopic, is conducive to enhancing product performance.
Detailed description of the invention
Referring to specific embodiment, the present invention is described.Those skilled in the art can manageSolving, these embodiments are merely to illustrate the present invention, and it limits the model of the present invention never in any formEnclose.
Embodiment 1: the preparation method of a kind of cemented carbide with complicated shape product:
It is (1) mixing: 75% cemented carbide powder and 25% binding agent are weighed according to weight ratio,Add in mixing roll.Wherein, binding agent consist of 75% paraffin, 5% high density polyethylene (HDPE),5% polypropylene and 15% stearic acid.Being heated to 140 DEG C at mixing machine, mixing time is 6h；
(2) pelletize: use extrusion device feeding to be extruded into banding, strip each three times, pass throughPulverizer is pelletized；
(3) injection moulding: the feeding after pelletizing uses injector to inject variously-shapedHard alloy injection base.Injection temperature is 160 DEG C, and injection pressure is 60MPa, and mould temperature is 30About DEG C；
(4) defat: use two step degreasing methods of solvent degreasing+thermal debinding.First in trichlorineRemoving portion of binder in ethylene solvent, skimming temp is 50 DEG C, and degreasing time is 7h.HeatDefat uses defat under N2 atmosphere, and skimming temp is 470 DEG C, removing residue binding agent；
(5) pressure sintering: using pressure sintering in sintering furnace, sintering temperature is 1420 DEG C,Temperature retention time is 60min, and pressure is 5MPa.
Embodiment 2: the preparation method of a kind of cemented carbide with complicated shape product
It is (1) mixing: 75% cemented carbide powder and 25% binding agent are weighed according to weight ratio,Add in mixing roll.Wherein, binding agent consist of 70% paraffin, 5% high density polyethylene (HDPE),5% polypropylene and 20% stearic acid.Being heated to 140 DEG C at mixing machine, mixing time is 6h；
(2) pelletize: use extrusion device feeding to be extruded into banding, strip each three times, pass throughPulverizer is pelletized；
(3) injection moulding: the feeding after pelletizing uses injector to inject variously-shapedHard alloy injection base.Injection temperature is 160 DEG C, and injection pressure is 60MPa, and mould temperature is 30About DEG C；
(4) defat: use two step degreasing methods of solvent degreasing+thermal debinding.First in trichlorineRemoving portion of binder in ethylene solvent, skimming temp is 50 DEG C, and degreasing time is 7h.HeatDefat uses defat under N2 atmosphere, and skimming temp is 470 DEG C, removing residue binding agent；
(5) pressure sintering: using pressure sintering in sintering furnace, sintering temperature is 1390 DEG C,Temperature retention time is 60min, and pressure is 5MPa.
The above, be only presently preferred embodiments of the present invention, not makees the present invention anyPro forma restriction, although the present invention is disclosed above with preferred embodiment, but and be not used toLimiting the present invention, any those skilled in the art, without departing from technical solution of the present inventionIn the range of, when the technology contents of available the disclosure above makes a little change or is modified to equivalent changeThe Equivalent embodiments changed, as long as being the content without departing from technical solution of the present invention, according to the present inventionTechnical spirit to any simple modification made for any of the above embodiments, equivalent variations and modification, allStill fall within the range of technical solution of the present invention.