What aluminous piston processes cutting tool data is reasonable choose

1 tall hardness and wearability hardness are the main character that cutting tool material should have. Cutting tool should cut next cutting from workpiece bits, the hardness that its hardness must compare workpiece data is big. Cutting metal place uses the cutting blade hardness of cutting tool, be in commonly 60HRC above. Wearability is ability of material resistance tatty. Generally speaking, the hardness of cutting tool material is taller, its wearability is better. The horniness in the organization is nodded (carbide, nitride) hardness is taller, the amount is more, grain is less, distributing evener, criterion wearability is better. Wearability returns the temperature of the chemical composition with material, intensity, microstructure and attrition area to concern. Usable formula expresses the wearability WR of material: WR=KIC0.

5E-0.

8H1.

In 43 type: H -- material hardness (GPa) . Hardness heals tall, wearability has healed. KIC -- of material rupture tenacity (MPa · M½) . KIC heals big, criterion material suffers what stress causes to rupture more small, wearability has healed. E -- the stretch model of material is measured (GPa) . E very hour, what because wear bead,cause is microscopical meet an emergency, conduce to the stress with inferior generation, wearability rises. 1.

2 enough strength and tenacity should make cutting tool is in bear very great pressure, and the job below the concussion that often appears in cutting process and oscillatory condition, and do not produce collapse blade and break off, cutting tool material must have enough strength and tenacity. 1.

3 tall hear resistance (thermal stability) hear resistance is the main mark that measures performance of cutting of cutting tool material. It is the function of sex of He Ren of the hardness that points to cutting tool material to keep certain below high temperature condition, wearability, intensity. Cutting tool material still should be had the ability that fights oxidation below high temperature and fight goodly felt and fight diffusing ability, namely cutting tool material should have good chemical stability. 1.

4 good hot physics performance and the thermal conductivity that heat-resisting pounds material of function cutting tool had healed, heat in metal cutting comes loose easily from cutting area more, be helpful for dropping cutting temperature. Cutting tool is when interrupted cutting or use cutting fluid, often get very big thermal shock (temperature change is acuteness) , consequently cutting tool interior can produce crackle and bring about rupture. Cutting tool material touchs heatproof percussive ability to be able to pound coefficient R to express with heat-resisting, the definition of R is to be: In type of α of B(1-µ)/E of R= λ σ : λ -- coefficient of thermal conductivity; σ B -- tensile strength; µ -- Poisson comparing; E -- stretch model quantity; α -- hot coefficient of expansion. Coefficient of thermal conductivity is big, make quantity of heat comes loose easily, reduce the temperature gradient of cutting tool surface; Hot coefficient of expansion is small, can reduce heat to be out of shape; Stretch model amount is small, because heat up what be out of shape and arise to hand in,can reduce change the extent of stress; Be helpful for what material heat-resisting pounds function rising. Heat-resisting pounds the cutting tool stuff with good performance, cutting liquid can be used when cutting is machined. 1.

5 good technical properties to facilitate the production of cutting tool, material of requirement cutting tool has good technical properties, if forging,plasticity of function, heat treatment function, high temperature is out of shape function, grinding machines function to wait. 1.

6 economy economy is one of main index of cutting tool material, although material of high grade cutting tool is odd a cutting tool cost is very high, but because of its service life grows, apportion arrives the cost of every spare parts is not fixed very tall. Because this wants when choosing cutting tool material,consider its economy effect integratedly. Material of 2 cutting tool 2.

High-speed steel of 1 high-speed steel is one kind joined the tall alloy tool of the alloying element such as more tungsten, molybdenum, chromic, vanadium steel. High-speed steel has higher intensity and tenacity, and have certain hardness and wearability. Fit the requirement of of all kinds cutting tool. Workmanship of high-speed steel cutting tool is simple, easy wear is sharp cutting blade, although data of all sorts of new-style cutting tool are constant,appear accordingly, high-speed steel cutting tool still holds larger proportion in metallic cutting. Can machine nonferrous metal and high temperature alloy. Because high-speed steel has above property, the mill in piston treatment irrigates horizontal chamfer of rising head, mill and mill to expand groove uses cutting tool of first class of the milling cutter, Kong Yongzuan that get oil to be high-speed steel material. 2.

Hard alloy of 2 hard alloy is by carbide of difficult frit metal (wait like WC, TiC, TaC, NbC) with metallic binder (wait like Co, Ni) the method of metallurgy of pulverous classics powder is made. Because many metallic carbide is contained in hard alloy, these carbide have melting point tall, hardness is chemical and tall, stable thermal stability is good, good wait for a characteristic, accordingly, the hardness of hard alloy material, wearability, hear resistance is very tall. The hardness of commonly used hard alloy is 89 ～ 93HRA, the hardness that compares high-speed steel (83 ～ 86.

6HRA) is tall, in 800 ～ 1000 ℃ vogue can undertake cutting. When 540 ℃ , the hardness of hard alloy is 82 ～ 87HRA, when 760 ℃ , hardness still can maintain 77 ～ 85HRA. Accordingly, the cutting function of hard alloy is gotten higher than high-speed steel much, cutting tool durability can rise to arrive severalfold a few times, when durability is identical, cutting rate can rise 4 ～ 10 times. The hard alloy cutting tool that at present my company uses basically is YG kind (the YG6 in WC-TiC-Co) and YGX. YT kind (the hard alloy such as the YT15 in WC-TiC-Co) is used at piston rough machining, semifinishing machining and working procedure of partial finish machining. 2.

3 diamond diamond is current the hardness in foregone and mineral material is highest, hot the material with best conductibility, the 1/50 ～ 1/800 that is hard alloy only with the wear extent that conjugate of all sorts of metals, metalloid material chafes, it is material of optimal of cutting tool of the cutting that make. However, diamond of natural single crystal is used at making the superprecision of headgear and certain nonferrous metal only. Cutting tool choose and employ persons makes big grain single crystal although diamond is current De Beers company, live friendly electrician all industrialized already production, but had not entered many application phase. The cutting blade of diamond cutting tool is very sharp (of this dinky to be being cut section cutting bits is very important) , blade ministry surface roughness is very small, coefficient of friction low, not easy generation accumulates bits tumour when cutting, treatment surface quality is high. When machining nonferrous metal, exterior surface roughness can achieve Ra0.

012µm, treatment precision can achieve IT5 class above. Diamond cutting tool has 3 kinds: Man-made of cutting tool of diamond of natural single crystal, whole gets together brilliant diamond cutting tool, diamond is compound cutting tool. Natural diamond cutting tool because cost is more advanced reason, the application in be being produced actually is less. Making synthetic diamond is the action that carries alloy catalytic agent, be changed by black lead below high temperature high pressure and become. Diamond is compound bit is to be on hard alloy matrix the advanced technology agglomeration such as course high temperature, high pressure is made an appointment with one layer 0.

The diamond with 5 ～ thick 1µm, this kind of material is do matrix with hard alloy, its machinery function, hot conductibility and coefficient of expansion are approximate at hard alloy, the diamond crystal in the abrasive of diamond of man-made much brilliant on matrix is shown irregular arrange, its hardness and wearability are in each direction are even. Get together brilliant diamond (abbreviation PCD) is the making synthetic diamond that chooses by the course microcrystalline body issues agglomeration in high temperature high pressure and become. In agglomeration process, as a result of the affiliation of additive, make be formed between diamond crystal wait for the combinative bridge that is bases with TiC, SiC, Fe, Co and Ni. Diamond crystal is formed with the union of covalent bond in setting the firm framework that forms at structural bridge firmly, make the intensity of PCD and tenacity rise greatly, its hardness is 9000HV about, bending strength is O.

21 ～ 0.

48GPa, coefficient of thermal conductivity is 20.

9J/cm · Sµ ℃ , hot coefficient of expansion is 3.

℃ of 1 × 10-6/ . Use now get together brilliant diamond cutting tool is the complex system that PCD and agglomeration of hard alloy matrix form mostly, go up in the agglomeration on hard alloy matrix namely a PCD. The ply of PCD is commonly 0.

5mm and 0.

8mm, because ground floor is hard alloy, solder convenient; Combine the conductivity of the bridge as a result of PCD again, make PCD facilitates cut processes all sorts of form, make all sorts of cutting tool, cost far under natural diamond. Get together brilliant diamond (PCD) can be machined all sorts of nonferrous metal and extremely the high-powered metalloid data of wear-resisting, if aluminous, copper, magnesium reachs its alloy, hard alloy, fiber increases plastic, metallic radical composite material, lumber composite material. Grain of the diamond in material of PCD cutting tool is average measurement is different, the effect that produces to function is distinct also, grain size is larger, its wearability is taller. In the point of close treatment capacity falls, grain size is smaller, criterion point quality is better. Choose grain dimension to be the PCD cutting tool of 10 ～ 25µm, can the content of Si of high speed cutting of 500 ～ 1500m/min 12 ～ the silicon aluminium alloy of 18% , the content of PCD treatment Si of 8 ～ 9µm is less than grain dimension the aluminium alloy of 12% . Superprecision, should choose the PCD cutting tool with grain small size. The wearability of PCD will be abate when more than 700 ℃ , because metallic Co is contained in its structure, can promote " converse reaction " transform to black lead by diamond namely. PCD has better rupture tenacity, can undertake interrupted cutting, can carry mill Si content with the high speed of 2500m/min the aluminium alloy of 10% . The tall hardness that can use diamond data, tall wearability, tall thermal conductivity and nonferrous metal of implementation of low coefficient of friction and wear-resisting are the high accuracy of metalloid material, efficient, tall stability and fast face are bright and clean spend treatment. When cutting machines nonferrous metal, the life of PCD cutting tool is hard alloy cutting tool a few times even hundreds of times, it is the ideal cutting tool that at present aluminous piston nicety machines. For example: Piston pin of boring of chamfer of annulus of fine vehicle piston, essence the working procedure such as end face of piston of vehicle of the circle outside piston of vehicle of aperture, fine, fine. 2.

4 cubic nitrogen change boron to get together nitrogen of brilliant cubic metre changes boron (PCBN) is by CBN small pink with a few felt photographs (Co, ni or TiC, TiN, Al203) joins activator agglomeration below high temperature high pressure and become. It has very tall hardness (be next to diamond) with hear resistance (1500 ℃ of 1300 ～ ) , get much thermal stability excellent chemical stability, higher than diamond cutting tool (amount to 1400 ℃ ) with thermal conductivity, low coefficient of friction, dan Jijiang is spent inferior. Compare with diamond photograph, the outstanding advantage of PCBN is thermal stability is gotten high much, can amount to 1200 ℃ (diamond is 700 ～ 800 ℃ ) , can bear higher cutting rate; Another outstanding advantage is chemical laziness big, with metal of iron a group of things with common features is below 1300 ℃ of 1200 ～ also do not have chemical reaction, can use at processing iron and steel. Accordingly, PCBN cutting tool basically is used at material of difficult treatment of efficient treatment black. PCBN cutting tool besides the characteristic that has above, still have the following advantages: ① hardness is tall, special agree with treatment once upon a time can the heat-resisting alloy of above of the hard steel of temper by dipping in water of the HRC50 above of grinding, HRC35 and HRC30 are the following and other cutting tool is very difficult the grey mouth of treatment is cast-iron. ② and photograph of hard alloy cutting tool are compared, cutting rate is high, can realize high speed efficient cutting. ③ wearability is good, cutting tool durability is tall (the 10 ～ that are hard alloy cutting tool 100 times) , can acquire better workpiece surface quality, implementation is ground with car generation. The anti-impact properties that insufficient place depends on PCBN cutting tool relatively hard alloy is poor, accordingly, what when using, should notice to raise machining complex is rigid, avoid to pound cutting as far as possible. PCBN can make integral bit, also can make compound bit with hard alloy union. PCBN compound razor blade is to be on hard alloy matrix agglomeration 0.

5 ～ 1.

The PCBN with thick 0mm, its function holds better tenacity and taller hardness and wearability concurrently. The function of PCBN basically reachs bond sort to concern with the content of the granuality of CBN, CBN, by its the organization can divide roughly it is two kinds big: One kind is be united in wedlock directly by CBN grain and become, CBN content is high (70% above) , hardness is tall, apply to heat-resisting alloy, cast-iron the cutting treatment that fastens agglomeration metal with iron; Another kind is with CBN grain gives priority to body, through bond of pottery and porcelain (basically TiN, TiC, TiCN, AlN, Al203 waits) agglomeration and into, content of the CBN in this kind of PCBN is low (70% the following) , hardness is low, apply to cutting to process hard steel of temper by dipping in water. Be in my company, in the process of chamfer of turning casting iron hoop that cubic nitrogen changes boracic cutting tool to be used at setting cast-iron annulus piston, also apply at the piston at the same time in the treatment of stereo profiling. 2.

The main good point of material of cutting tool of pottery and porcelain of 5 pottery and porcelain is: Have very tall hardness and wearability, normal temperature hardness amounts to 91 ～ 95HRC; Have very tall hear resistance, below 1200 ℃ high temperature hardness is 80HRC; And the bending strength below high temperature condition, tenacity is reduced few; Have very tall chemical stability, pottery and porcelain and metallic affinity are small, it is good that high temperature fights oxidation function, although be below fused temperature also not with steel interaction. Consequently the felt of cutting tool, diffuse, oxidation wears away less; Have inferior coefficient of friction, cut bits to stick a knife not easily, not easy generation accumulates bits tumour. The defect of knife of pottery and porcelain is: Brittleness is big, intensity and tenacity are low, bending strength has the 1/2 ～ 1/5 of hard alloy only, because of appropriate geometrical parameter and cutting dosage must choosing when this is used; Avoid to bear concussion bear, die in case blade and damaged; In addition, rate of heat conduction of knife of pottery and porcelain is low, it is the 1/2 ～ 1/5 of hard alloy only, hot coefficient of expansion is more expensive than hard alloy however 10 ～ 30% , heatproof concussion sex is poorer. Current, cutting tool of pottery and porcelain has not applied in process of aluminous piston treatment. The development of material of cutting tool of 3 brief summary is having conclusive effect to the progress of cutting technology. The diamond that the article introduced the place in cutting to use, get together the performance that nitrogen of brilliant cubic metre turns the cutting tool material such as boracic, pottery and porcelain, hard alloy, high-speed steel and suitable scope. Mechanism of cutting tool attaint is cutting tool material reasonable chosen theoretical foundation, the function of cutting tool material and workpiece material matchs add up to the crucial basis that manage is choice of material of cutting cutting tool, want the mechanical, physics according to cutting tool material and workpiece material and chemical function to choose cutting tool material, ability achieves favorable cutting result. With respect to the piston material chose the cutting tool when cutting is machined to elaborate. High-speed steel: The mill in piston treatment irrigates horizontal chamfer of rising head, mill and mill to expand groove uses milling cutter, first class of the Kong Yongzuan that get oil is high-speed steel material. Hard alloy: In each working procedure that cutting tool of hard alloy of series of YG, YD is machined at aluminous piston by wide application, especially piston rough machining and semifinishing machining working procedure. Cubic nitrogen changes boron: In the process of chamfer of turning casting iron hoop that cubic nitrogen changes boracic cutting tool to be used at setting cast-iron annulus piston. Also apply at the piston at the same time in the treatment of stereo profiling. Diamond: The tall hardness that diamond cutting tool can use diamond data, tall wearability, tall thermal conductivity and nonferrous metal of implementation of low coefficient of friction and wear-resisting are the high accuracy of metalloid material, efficient, tall stability and fast face are bright and clean spend treatment. When cutting aluminium alloy, the life of PCD cutting tool is hard alloy cutting tool a few times even hundreds of times, it is the ideal cutting tool that at present aluminous piston nicety machines, had applied at piston pin of boring of chamfer of annulus of fine vehicle piston, essence in the finish machining working procedure such as firebox of end face of piston of vehicle of the circle outside piston of vehicle of aperture, fine, fine and fine vehicle piston. CNC Milling CNC Machining