Crystal whisker toughened base titanium carbonitride cutting tip of SiC and preparation method thereof
Technical field
The present invention relates to a kind of material of tools, be meant the crystal whisker toughened composite carbon titanium nitride of a class [Ti (CN)] based ceramic metal cutter material especially.The invention still further relates to a kind of making method of above-mentioned materials.
Background technology
People's custom directly is called sintering metal with TiC/Ti (CN) based ceramic metal matrix material, and traditional WC-Co hard alloy composite material is called Wimet.Present mass-produced sintering metal cutting tip, great majority be with titanium carbonitride [Ti (CN)] as principal phase, with metal bonding mutually with the carbide hard as additive, by mixing moulding after high temperature sintering prepare.This sintering metal cutting tip is compared with traditional carbide cutting blade, has the red hardness height, advantages such as the sassafras coefficient is low, wear resistance good, erosion resistance height of rubbing, but bending strength and impelling strength can not show a candle to traditional carbide cutting blade.Compare with the TiC based ceramic metal, Ti (CN) based ceramic metal cutting tip red hardness height, cross-breaking strength height, oxidation-resistance is strong, thermal conductivity is high, and because Ti (CN) based ceramic metal crystal grain is thinner, its high-temperature creep resistance also improves significantly.In working angles, because it is higher that Ti (CN) forms enthalpy, can effectively avoid the formation of sticking cutter, cut and BUE, good wear of the tool flank performance can make cutter still keep long cutter life under higher cutting speed, and helps removing smear metal.Therefore, Ti (CN) based ceramic metal cutting tool is suitable for High Speed Milling Operation, finish turning or half finish turning carbon steel and stainless steel, even comprises materials such as the unmanageable superalloy of TiC base ceramet tool bit.Over past ten years, the research worker is in order to improve the structural ceramics composite material toughness, adopted methods such as transformation toughening, crystal whisker toughened and particulate reinforcement, but among groping always.So the developing direction of following Ti (CN) based ceramic metal still will improve constantly its intensity and toughness.
Summary of the invention
The objective of the invention is to improve the bending strength and the impelling strength of titanium carbonitride [Ti (CN)] based ceramic metal cutting tip, proposed the preparation method of the crystal whisker toughened Ti of a kind of SiC (CN) based ceramic metal cutting tip in order to overcome the weak point of prior art.By adding crystal whisker toughened dose of SiC, adopt the process program and the material prescription that upgrade to reach the bending strength of Ti (CN) based ceramic metal cutting tip and the raising of impelling strength, this class cutting tip is widely used.
Preparation method according to the crystal whisker toughened titanium carbonitride of a kind of SiC [Ti (CN)] the based ceramic metal cutting tip that purpose of the present invention proposed is: with titanium carbonitride [Ti (CN)] as principal phase, adopt the SiC whisker as toughner, with metal bonding mutually and the carbide hard as additive, pass through mixing moulding final vacuum sintering and form.Wherein the key problem in technology point is:
(1) raw material choice: titanium carbonitride [Ti (CN)] is a main raw material, with the SiC whisker as toughner, the whisker mean diameter is 0.5~1.0 μ m, length 10~40 μ m, 2700 ℃ of fusing points, theoretical density 3.2g/cm3, Young's modulus is 414GPa, thermal expansivity is 4.7 * 10-6/ ℃, add-on is 8%~30% of a gross weight, with metal molybdenum, nickel, cobalt, tantalum (Mo, Ni, Co, Ta) as bonding phase and carbide carbonization titanium (TiC), wolfram varbide (WC), niobium carbide (NbC) hard is as additive, the weight ratio of titanium carbonitride [Ti (CN)] and SiC whisker can be 65: 35~and 80: 20, its the two weight sum is W, metal Ni, Co, the add-on of Mo bonding phase is 51.7~58.6% of a weight W, hard phase TiC, WC, the add-on of NbC is 82.5~87% of a weight W.
(2) dispersion of SiC whisker: the SiC whisker is put into the mixture of polar solvent (as water, ethanol, b propanol etc.) and dispersion agent, make aaerosol solution through mechanical stirring and ultra-sonic oscillation, to guarantee SiC whisker stable dispersion.
(3) technological process: before not adding the SiC whisker, batching put in the stainless steel jar mill grind, mill ball is the WC-Co sintered carbide ball of 6mm, grinding medium is an alcohol, wet-milling 80-90 hour, the slip that adds forming agent and toughner draws off after drying and screening is granulated compression moulding on powder compaction press, the blade of densified sintering product in vacuum sintering furnace then.Concrete preparation technology is: batching → wet-milling → (adding binder and toughner) mixed slurry → drying → sieve → control grain → compression moulding → vacuum sintering → goods.
(4) vacuum sintering of material: the idiosome after the compression moulding is put into the vacuum sintering furnace sintering, and for the better densification of material, the vacuum sintering temperature is set to 1460 ℃~1570 ℃.
Have high strength, high tenacity and good cutting performance such as better wear resistance, thermotolerance by the produced Ti of the present invention (CN) based ceramic metal cutting tip.Be suitable for a series of superhard difficult to machine materials such as High Speed Milling Operation, finish turning or half finish turning carbon steel and stainless steel, quenched steel, alloy wear-resisting cast iron, high-strength steel.
Embodiment
The invention will be further described below in conjunction with embodiment.
The present invention is the crystal whisker toughened Ti of a kind of SiC (CN) based ceramic metal cutting tip, be as principal phase with titanium carbonitride [Ti (CN)], adopt the SiC whisker as toughner, with metal bonding mutually and the carbide hard as additive, pass through mixing moulding final vacuum sintering and form.Wherein the key problem in technology point is:
(1) raw material choice: titanium carbonitride [Ti (CN)] is a main raw material, with the SiC whisker as toughner, the whisker mean diameter is 0.5~1.0 μ m, length 10~40 μ m, 2700 ℃ of fusing points, theoretical density 3.2g/cm3, Young's modulus is 414GPa, thermal expansivity is 4.7 * 10-6/ ℃, add-on is 8%~30% of a gross weight, with metal molybdenum, nickel, cobalt, tantalum (Mo, Ni, Co, Ta) as bonding phase and carbide carbonization titanium (TiC), wolfram varbide (WC), niobium carbide (NbC) hard is as additive, and titanium carbonitride [Ti (CN)] can be 65: 35 with the weight ratio of SiC whisker~and 80: 20, its two weight sum is W.Molybdenum accounts for 17%~19.5% of gross weight W, and nickel accounts for 20%~22% of gross weight W, and cobalt accounts for 12.6%~13% of gross weight W, and tantalum accounts for 10.5%~15% of gross weight W.Titanium carbide accounts for 40.2%~43.5% of gross weight W, and wolfram varbide accounts for 25%~27% of gross weight W, and niobium carbide accounts for 16%~19% of gross weight W.
(2) dispersion of SiC whisker: the SiC whisker is put into the mixture of polar solvent (as water, ethanol, b propanol etc.) and dispersion agent, make aaerosol solution through mechanical stirring and ultra-sonic oscillation, to guarantee SiC whisker stable dispersion.
(3) technological process: before not adding the SiC whisker, batching put in the stainless steel jar mill grind, mill ball is the WC-Co sintered carbide ball of 6mm, and grinding medium is an alcohol, wet-milling 80-90 hour, adds crystal whisker toughened dose of uniform mixing of forming agent and SiC again; Again the slip that mixes is drawn off after drying and screening is granulated; Compression moulding on powder compaction press; The blade of densified sintering product in vacuum sintering furnace then.Concrete preparation technology is: batching → wet-milling → (adding binder and toughner) mixed slurry → drying → sieve → control grain → compression moulding → vacuum sintering → goods.
(4) vacuum sintering of material: the idiosome after the compression moulding is put into the vacuum sintering furnace sintering, and for the better densification of material, the vacuum sintering temperature is set to 1460 ℃~1570 ℃.
Embodiment one
Take by weighing the weight of titanium carbonitride and SiC whisker respectively, the weight ratio of its titanium carbonitride and SiC whisker is 70: 30; The SiC whisker is put into the mixture of polar solvent ethanol and dispersion agent, make aaerosol solution through mechanical stirring and ultra-sonic oscillation, standby to guarantee after the SiC whisker stable dispersion; The per-cent that adds weight [the weight sum of Ti (CN) and SiC whisker] in titanium carbonitride is 17.8% Mo, 20% Ni, 13% Co, 10.5% Ta, also have 43.5% TiC, 27% WC, 16% NbC, and mixed wet-milling 80 hours; Mixture that will be after wet-milling again with dispersive SiC whisker uniform mixing, compression moulding is then adopted vacuum sintering under 1460 ℃ temperature.Product is carried out the test of mechanical property, and its result is as follows: bending strength is 1600MPa, and fracture toughness property is 13.8MPa.ml/2, hardness HAC94.5.
Embodiment two
Take by weighing the weight of titanium carbonitride and SiC whisker respectively, the weight ratio of its titanium carbonitride and SiC whisker is 65: 35, the SiC whisker is put into the mixture of polar solvent b propanol and dispersion agent, make aaerosol solution through mechanical stirring and ultra-sonic oscillation, standby to guarantee after the SiC whisker stable dispersion; The per-cent that adds weight [the weight sum of Ti (CN) and SiC whisker] in titanium carbonitride is 19.5% Mo, 22% Ni, 12.6% Co, 10.8% Ta, also have 42% TiC, 27% WC, 17% NbC, and mixed wet-milling 90 hours; Mixture that will be after wet-milling again with dispersive SiC whisker uniform mixing, compression moulding is then adopted vacuum sintering under 1510 ℃ temperature.Product is carried out the test of mechanical property, and its result is as follows: bending strength is 1620MPa, and fracture toughness property is 14.2MPa.ml/2, hardness HAC94.2.
Embodiment three
Take by weighing the weight of titanium carbonitride and SiC whisker respectively, the weight ratio of its titanium carbonitride and SiC whisker is 76: 24, the SiC whisker is put into the mixture of water and dispersion agent, make aaerosol solution through mechanical stirring and ultra-sonic oscillation, standby to guarantee after the SiC whisker stable dispersion; The per-cent that adds weight [the weight sum of Ti (CN) and SiC whisker] in titanium carbonitride is 17% Mo, 20% Ni, 13% Co, 11.6% Ta, also has 40.2% TiC, 25% WC, 19% NbC, and mixes wet-milling 90 hours; Mixture that will be after wet-milling again with dispersive SiC whisker uniform mixing, compression moulding is then adopted vacuum sintering under 1570 ℃ temperature.Product is carried out the test of mechanical property, and its result is as follows: bending strength is 1590MPa, and fracture toughness property is 13.2MPa.lm/2, hardness HAC93.5.