CN1088993A

CN1088993A - The sintering metal manufacturing technology

Info

Publication number: CN1088993A
Application number: CN92114875A
Authority: CN
Inventors: 殷声; 郭志猛; 唐清; 果世驹; 钟吉华; 赖和怡
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 1992-12-31
Filing date: 1992-12-31
Publication date: 1994-07-06
Anticipated expiration: 2007-12-31
Also published as: CN1046317C

Abstract

The present invention relates to a kind of Technique for mfg. cermet, be characterised in that and adopt from climing combustion high-temperature synthesis (SHS), utilize chemical reaction self heat release to synthesize Al ₂O ₃And TiC, add simultaneously iron family element (Fe, Co, Ni) and group vib metallic element (Cr, Mo, W), by SHS synthetic-hot pressing or SHS be synthetic-pulverizings-hot pressing or SHS be synthetic-pulverizing-moulding-sintering process, prepares good toughness, intensity height, even tissue, and the low Al of cost ₂O ₃-TiC based ceramic metal, hardness HV18.0～20.0GPa, bending strength 600～850MPa, fracture toughness KIC 4.5～6.0MPam ^1/2Processing hardened steel, cutter life is than traditional hot pressing Al ₂O ₃Long 2～3 times of-TiC base cutter.

Description

The sintering metal manufacturing technology

The invention belongs to ceramic materials preparation technology field.

The Al that the conventional hot-press method is made ₂O ₃-TiC pottery and Al ₂O ₃-TiC based ceramic metal remains the sintex of consumption maximum so far as the existing 20 years history of cutter material, is widely used in the processing of quenched and tempered steel, hardened steel, cast iron, graphite and rubber etc.This class pottery is to adopt Al ₂O ₃After heat is pressed into through mixing with the powder such as TiC.This technology is difficult to obtain the material that crystal grain is tiny, be evenly distributed mutually, cost height.

From climing combustion high-temperature synthesis (SHS) is to utilize exothermic heat of reaction to prepare the new technology of material, and energy consumption is low, processing unit is simpler, good product quality.R。A。Culter etc. adopt the SHS legal system for fine and close Al ₂O ₃-TiC pottery (" Synthesis and Densification of Oxide-Carbide Composites ", Ceram Eng.Sci.Proc.6 (7-8), 715-728,1985) .SHS legal system is for Al ₂O ₃The Toughness Ratio of-TiC pottery tradition hot pressed ceramics good.But the fragility of pottery has still limited its extensive use.

The objective of the invention is to utilize the standby Al of SHS legal system ₂O ₃-TiC based ceramic metal adds metallic addition, improves the toughness of material, enlarges the scope of application, reduces cost.

Design of the present invention is: adopt the synthetic Al of SHS method ₂O ₃-TiC matrix adds metal adhesive simultaneously, and the uniform cermet of formative tissue in the SHS course of reaction, forms Al simultaneously ₂O ₃And TiC, growing up of they is subjected to each other inhibition.Therefore, can obtain the tissue that crystal grain is tiny, be evenly distributed mutually.Simultaneously, add binding metal with Al ₂O ₃-TiC combines the good cermet of formation strength high toughness.It is described in detail as follows:

1.TiO ₂, Al and C be main reaction mass, presses reaction equation TiO ₂+ Al+C → TiC+Al ₂O ₃+ Q forms basis Al ₂O ₃And TiC, Q is exothermic heat of reaction.In above-mentioned reaction mass, add a kind of or two kinds of iron family element tings (Fe, Co, Ni), as metal adhesive.Simultaneously, add a kind of or two kinds of group VIB metallic elements (Cr, Mo, W), form the carbide of these elements and the solid solution of TiC by reaction, in order to improve the iron group binding metal to the wetability of TiC, in order to promote Al ₂O ₃Sintering and suppress its grain growth, also add a small amount of MgO, NiO or TiO ₂Deng oxide.

2. in cermet, the total amount of ceramic phase is 80～95wt%, and wherein, the TiC amount is 20～60wt%, by adding Al ₂O ₃Powder or excessive TiO ₂Adjust Al with C ₂O ₃Ratio with TiC.MgO or NiO, TiO ₂Content be 0.1～1wt%.

3. in sintering metal, the total amount of metal additive is 5～20wt%.Wherein, the iron family metal amount is 1～15wt%, with the form adding of metal-powder.The amount of group VIB element is 1～10wt%, adds with the formation of metal dust, and formation that also can metal oxide adds.

4.Al ₂O ₃-TiC based ceramic metal can prepare by following technology.

(1) SHS-pressure sintering: carry out hot pressing when the SHS reaction takes place material, this technique process is few, and cost is low.

(2) SHS synthetic-fragmentation-hot pressing: the synthetic material is broken into batch mixing behind the powder, carries out hot pressing;

(3) SHS synthetic-fragmentation-moulding-sintering: the synthetic material is broken into sintering after batch mixing behind the powder, the compression molding.

Adopt SHS manufactured Al ₂O ₃-TiC based ceramic metal, density 4.2～4.6 gram per centimeters ³, hardness Hv is 18.0～20.0GPa, bending strength 600～850MPa, fracture toughness property K _ICBe 4.5～6MPam ^1/2Cutter is processed 55 steel (HRc50 that hardens～55), and cutting speed is 110m/min, and during tool wear 0.24mm, the cutting time is 90min.

The invention has the advantages that than traditional hot pressing Al ₂O ₃-TiC cutter life increases by 3 times, and technology is simple, and cost is low.

Example 1:

58 gram TiO ₂Powder (100 order), 26 gram Al powder (200 order), 8.5 gram carbon blacks, 4 gram Ni powder (200 order), 3 gram Mo powder (200 order) and 0.5 gram MgO sphere of powder mill 24 hours.The test portion that mixes is packed in the graphite jig, carries out SHS-hot pressing on the direet-heating type thermocompressor, and when mold heated during to about 1400 ℃, test portion reacts, and (200kg/cm immediately exerts pressure ²) carry out hot pressing.This moment, the test portion temperature reached 1700～1900 ℃.Hot pressing can obtain fine and close Al about 10 seconds ₂O ₃-TiC-Ni, (Mo) cermet.Density 4.6g/cm ³, hardness Hv 19.0GPa, bending strength 850MPa, fracture toughness property KIC5.5MPam ^1/2Tool in Cutting result as previously mentioned.

Example 2:

58 gram TiO ₂Powder (100 order), 26 gram Al powder (200 order) and 8.5 gram carbon blacks mixed after 8 hours, inserted small-sized SHS reactor and synthesized.Synthetic material is ground into powder through ball milling 24 hours.Add 4 gram Ni powder (200 order) in the synthetic powder again, 3 gram Mo powder (200 order) and 0.5 gram MgO powder, ball milling 24 hours.The material that mixes is packed in the graphite jig, hot pressing on the direet-heating type thermocompressor, 1650～1700 ℃ of hot pressing temperatures, pressure 200kg/cm ², 10 minutes time, just can obtain the compact metal pottery.Density 4.65g/cm ³, hardness Hv19.2GPa, bending strength 800MPa, fracture toughness property K _IC5.4MPam ^1/2

Example 3:

68 gram TiO ₂Powder, 31 gram Al powder, 9 gram carbon blacks and 62 gram Al ₂O ₃Powder (400 order) mixed 8 hours, and the reaction test portion borrows the tungsten filament heating to light, synthetic Al in the SHS reactor ₂O ₃+ TiC.Synthetic material was through 24 hours ball milling powdereds.Synthetic powder adds 6 gram Ni powder again, and 4 gram Mo powder and 1 gram MgO powder were through ball milling 24 hours.The stamping of powder moulding that mixes, sintering is carried out at the vacuum carbon-tube oven in the back.1700～1800 ℃ of sintering temperatures, obtain the compact metal pottery at 1 hour time.Density 4.3 gram/cm ³, hardness Hv18.6GPa, bending strength 605MPa, fracture toughness property KIC 4.5MPam ^1/2

Claims

1, a kind of Technique for mfg. cermet is characterized in that adopting from climing combustion high-temperature synthesis (SHS), utilizes chemical reaction self heat release to synthesize Al ₂O ₃And TiC, add simultaneously metallic addition: a kind of or two kinds of iron family elements (Fe, Co, Ni) and a kind of or two kinds of group VIB metals (Cr, Mo, W) form cermet.

2, Technique for mfg. cermet according to claim 1 is characterized in that the ceramic phase total amount is 80～95wt%, and wherein the TiC amount is 20～60wt%, MgO or NiO or TiO ₂Amount is 0.1～1%, and all the other are Al ₂O ₃; Ceramic-metallic forming method can be selected a kind of in following method: hot pressing when SHS is synthetic; SHS synthesizes-pulverizes (mixing)-hot pressing; SHS synthesizes-pulverizes (mixing)-compacting-sintering.

According to the described sintering metal manufacturing technology of claim 1, it is characterized in that 3, the metal additive total amount is 5～20wt%, wherein the iron family metal is 1～15wt%, and group VIB metallic element amount is 1～10wt%.