CN1500579A

CN1500579A - Hot-pressing sintering method and mould for ceramic, carbide porous products

Info

Publication number: CN1500579A
Application number: CNA021340641A
Authority: CN
Inventors: 李家杰; 郑直; 谭竹峰; 梅华
Original assignee: Zigong Cemented Carbide Co Ltd
Current assignee: Zigong Cemented Carbide Co Ltd
Priority date: 2002-11-15
Filing date: 2002-11-15
Publication date: 2004-06-02
Anticipated expiration: 2022-11-15
Also published as: CN1257034C

Abstract

The present invention is heat pressing and sintering process and mold of ceramic and hard alloy product with hole. The heat pressing and sintering process includes cold pressing powder material to form plain blank, painting demolding agent, mounting partitioning boards, mandril and upper and lower punching head of hot pressing mold, and heat pressing and sintering inside a hot press and at 10-50 MPa pressure and 1200-2000 deg.c temperature. The hot pressing mold includes mold jacket, partition boards and mandril inside the mold cavity, and upper and lower punching head. The process can produce over 100 pieces of heat pressed and sinter product and has the advantages of less impurity mixed, high product quality, low production cost, long mold service life, etc.

Description

The hot-pressing sintering method and the mould of pottery, carbide porous products

Technical field

The invention belongs to pottery and CEMENTED CARBIDE PRODUCTION method and adopt the mould of this method, the particularly a kind of hot-pressing sintering method of many goods with holes of single mode multilayer, each layer and mould that this method adopted of adopting.Especially be suitable for the production of pottery and carbide porous blade etc.

Background technology

At present, hot pressing and sintering technique in pottery, the hard metal article production is to adopt the powder that directly adds the goods prescription in mould, be heated to sinter molding under 1200 °～2000 ℃ and the pressure on the hot press indirectly or directly then, the blank after the moulding or again through grinding or through cutting into finished products such as circle, square, triangle, rhombus at 10～50Mpa.This method is owing to adopt Thermocompressed sintering and forming behind the loose powder adding die cavity, both existed and easily brought impurity into, cause quality of item to reduce, existing again can not direct sintering goods with holes, and goods easily and the disadvantage of die cavity adhesion, mold damage, can only produce 1～2 owing to single mode in addition at every turn, thereby have the defective that productivity ratio is low, production cost is high again.

Summary of the invention

The objective of the invention is defective at the background technology existence, research and design is a kind of to adopt more than single mode multilayer, each layer pottery, the hot-pressing sintering method and the mould of carbide porous products, boost productivity and Products Quality to reach, effectively reduce production costs, prolong purposes such as die life.

Solution of the present invention is the pottery or the carbide alloy powder of the need hot pressed sintering that will prepare earlier, cold pressing and make goods biscuit (blank) with holes and again the biscuit layering is packed in the die cavity, separate with dividing plate between layer and the layer, evenly coat releasing agent in the surface of blank and the hole, plug passes the endoporus of blank, upper and lower drift from the upper and lower pressurization simultaneously of die cavity, withdraws from die cavity and plug through the good goods of hot pressed sintering respectively, just makes required pottery and carbide porous products through grinding dressing.Therefore, the inventive method comprises:

A, compacting biscuit: pottery that will prepare or carbide alloy powder are measured on request and are placed conventional pressing mold to be cold-pressed into goods biscuit (blank) with holes, and the intensity that makes biscuit reaches 30～50% of goods final strength, the demoulding, dry back on the biscuit surface and endoporus evenly coat releasing agent, airing is stand-by;

B, releasing agent is also coated on all surfaces that contacts with biscuit on hot pressing die inner chamber, dividing plate, plug, behind the airing with the biscuit proper alignment on the dividing plate of each layer, last layer is also established a dividing plate, simultaneously, plug is through in the hole of each biscuit, and the upper and lower drift of packing into;

C, hot-forming: the mould of the biscuit of will packing into places in the hot press, and hot pressed sintering is 30～90 minutes under 10～50Mpa pressure and 1200 °～2000 ℃ temperature, and the demoulding after cooling off, grinding dressing get product again.

Above-mentioned in 1200 °～2000 ℃ temperature ranges hot pressed sintering, its mode of heating both can be direct heating, also can adopt indirect.And described pottery and carbide alloy powder both can contain binding agent, also can not contain binding agent; And dried biscuit both can remove binding agent, also can not remove binding agent.

And the hot pressed sintering that above-mentioned hot-pressing sintering method adopted comprises die sleeve, die cavity, drift with mould; Key is also to comprise the dividing plate with the cored bar hole of each layer blank (being biscuit) and blank and drift isolation, inserts in the plug in the blank hole; Drift then is upper and lower drift; Each dividing plate cooperates with the die cavity wall activity and can be along the upper and lower slip of mould intracavity wall, and upper and lower drift is then movable to be placed on the corresponding upper and lower dividing plate.

And described die sleeve is inside and outside die sleeve, and its die cavity both can be the parallelogram die cavity according to article shape, the porous type die cavity that the cylindrical hole of the isolation mutually of also can serving as reasons is formed.And described plug both can be the short plug that is used respectively with each blank, also can be the blank of upper and lower correspondence and dividing plate, the long plug of drift series connection all-in-one-piece; When for long plug, each the plug hole on the dividing plate is through hole.

The present invention is owing to adopt elder generation that raw meal is cold-pressed into biscuit, adopt more than multilayer, each layer hot pressing die again, Thermocompressed sintering and forming on hot press, in sintering process, be difficult for bringing into impurity, can adhesion between blank and die cavity and the blank, one time the hot pressing sintering reaches more than 100 goods such as triangle with holes, quadrangle or circle, and mould can use more than ten times repeatedly.Quality of item is good, profile is neat thereby have, and production cost is low, and productivity ratio can improve characteristics such as ten to tens of times and die life be long than background technology.

Accompanying drawing and description of drawings

Fig. 1, for structure of the present invention and user mode schematic diagram;

Fig. 2, be the vertical view (A-A view) of Fig. 1;

Fig. 3, be embodiment 2 structures and user mode schematic diagram; Fig. 4 is its vertical view.

Among the figure: 1, outer die casing, 2, interior die sleeve, 3, upper punch, 4, plug, 5, dividing plate, 6, blank, 7, low punch, 8, die cavity.

Embodiment 1

Present embodiment is an example to produce 16.5 * 16.5 * 8.5mm blade with holes:

A, at first with the AI of conventional requirement ₂O ₃/ SiCw composite powder places pressing mold to be cold-pressed into 16.5 * 16.5 * 18mm biscuit (blank 6), biscuit centre bore φ 6mm, and the BN releasing agent is evenly coated in dry a little back in each biscuit surface and hole, and dry back is stand-by;

B, also evenly coat the BN releasing agent with the contact-making surface of blank 6 and the surface of plug 4 at the inwall of die cavity 8 and dividing plate 5, and airing, after then low punch 7 and base spacer 5 being loaded on the bottom of die cavity 8, put biscuit (being blank 6), dividing plate more successively, insert plug 4 and upper punch 3 at last, present embodiment is put 6 layers of totally 54 biscuits, 7 dividing plate;

C, be placed in the above-mentioned interior die sleeve 2 of loading onto biscuit in the outer die casing 1 after, place in 40 tons of vacuum hotpressing machines, hot pressed sintering is 60 minutes under 35Mpa pressure and 1600 °～1680 ℃ temperature, and the demoulding promptly gets hot-pressed product after cooling off then, and these goods are end article through grinding slightly.

Present embodiment outer die casing 1, interior die sleeve 2, upper and lower drift: 3,7, dividing plate 5 and plug 4 all adopt high purity graphite to make, wherein: outer die casing 1, internal diameter φ 100mm, wall thickness 30mm, high 260mm; Interior die sleeve 2 external diameter φ 100mm, die cavity 8 shaft sections 41.0 * 41.0mm, height also are 260mm; Dividing plate 5 and upper and lower drift 3,7 shaft sections are 40.5 * 40.5mm, and plug hole is φ 5.4mm on it, the thick 8mm of each dividing plate, the thick 50mm that is of upper and lower drift; Plug 4 diameter phi 5.2mm, long 270mm.

Embodiment 2

Present embodiment is an example with the goods of producing φ 16.5 * 8.5:

At first with Si ₃N ₄Composite powder is colded pressing and is made the biscuit that φ 16.5 * 18mm center bore is φ 6.0mm (blank 6), and totally 42, each die cavity is adorned base separately, and dress base and sintering method and embodiment 1 are together.

The inside and outside footpath of outer die casing 1 in the present embodiment mould, high and in die sleeve 2 external diameter, high all with embodiment 1 together, die cavity 8 present embodiments adopt 7 cylinder hole shape die cavitys that diameter is φ 16.65mm, upper and lower drift 3,7 also respectively is the drift in 7 cored bar holes 4, punch diameter φ 16.5mm, height is 50mm; Dividing plate 5 diameters are φ 16.5mm, thick 8mm, totally 49; Plug bore dia φ 5.4mm; Plug 4 long 270mm, diameter phi 5.2mm.The material of above-mentioned each parts of mould also is high purity graphite.

Claims

1, the hot-pressing sintering method of a kind of pottery, carbide porous products; It is characterized in that this method comprises:

A, compacting biscuit: pottery that will prepare or carbide alloy powder are measured on request and are placed conventional pressing mold to be cold-pressed into goods biscuit with holes, and the intensity that makes biscuit reaches 30～50% of goods final strength, the demoulding, dry back on the biscuit surface and endoporus evenly coat releasing agent, airing is stand-by;

B, releasing agent is also coated on all surfaces that contacts with biscuit on hot pressing die inner chamber, dividing plate, plug, behind the airing with the biscuit proper alignment on the dividing plate of each layer, last layer is also established a dividing plate, simultaneously plug is through in the hole of each biscuit, and the upper and lower drift of packing into;

2, press the hot-pressing sintering method of the described goods with holes of claim 1; It is characterized in that described hot pressed sintering, its mode of heating both can be direct heating, also can adopt indirect.

3, press the hot-pressing sintering method of the described goods with holes of claim 1; It is characterized in that described pottery and carbide alloy powder both can contain binding agent, also can not contain binding agent; And dried biscuit both can remove binding agent, also can not remove binding agent.

4, by the hot-pressing sintering method mould therefor of the described goods of claim 1, comprise die sleeve, die cavity, drift; It is characterized in that also comprising dividing plate, insert in the plug in the blank hole the cored bar hole of each layer blank and blank and drift isolation; Drift then is upper and lower drift; Each dividing plate cooperates with the die cavity wall activity and can be along the upper and lower slip of mould intracavity wall, and upper and lower drift is then movable to be placed on the corresponding upper and lower dividing plate.

5, by the described mould of claim 4; It is characterized in that described die sleeve is inside and outside die sleeve, its die cavity both can be the parallelogram die cavity according to article shape, the porous type die cavity that the cylindrical hole of the isolation mutually of also can serving as reasons is formed.

6, by the described mould of claim 4; It is characterized in that described plug both can be the short plug that is used respectively with each blank, also can be the blank of upper and lower correspondence and dividing plate, the long plug of drift series connection all-in-one-piece; When for long plug, each the plug hole on the dividing plate is through hole.