Material of new-style cutting tool -- rare earth hard alloy

In contemporary machining, cutting tool material is used at most with hard alloy and high-speed steel, take an in part each almost. The invention of high-speed steel and application, already had full the history of a century, hard alloy already had half century. But both all develops an a lot of new breed, its function rises ceaselessly, main effect is being produced in machining. The hard alloy that adds rare-earth element is one of new breed of cutting tool material. Rare-earth element is the atomic number in pointing to chemical periodic chart 57 ～ 71(arrives from La Lu) , plus 21 with 39(Sc and Y) , in all 17 elements. certain rare-earth element, with certain kind, minim is added in traditional hard alloy brand, can improve their mechanical function and cutting performance effectively. Our country rare-earth element is resourceful, to rare earth the research of hard alloy is developed, banner at other country. The cutting tool that already developed a following shop sign uses rare land hard alloy: YG8R(is equivalent to ISO K30 level) , YG6R(K20) , YW1R(M10) , YW2R(M20) , YT5R, YT14R(P20) , YT15R(P10) , YS25R(P25) . Still have YG11CR of brand of mine, geological tool. The author is right afore-mentioned P kind, M kind, K kind the cutting function of hard alloy all made rare land experiment research of the system, discussed their cutting mechanism. Function of the machinery of hard alloy, physics is in rare earth after Ce, Y was being added to wait for rare-earth element in hard alloy of YG8, YT14, YW1, formed rare earth hard alloy YG8R, YT14R, YW1R. YG8R basically uses the rough machining of Yu Zhu iron and nonferrous metal; YT14R basically uses the semifinishing machining of rolled steel; YW1R is current name, can use at the semifinishing machining of all sorts of workpiece material. The course checks, the organization of the hard alloy after adding rare-earth element is more compact; Room temperature hardness and high temperature hardness are improved somewhat; Rupture tenacity and bending strength rise significantly, rise respectively 20% with 10% above. The wear-resisting caustic of hard alloy and in use life test traverse rare land experiment we know, compare with the photograph of former razor blade that does not have rare-earth element, the wearability of razor blade of YG8R, YT14R, YW1R and service life all have different rate rise. We still had rare land the impact test of hard alloy, wait for the hard alloy bit that adds rare-earth element with YG8R, YT14R, YW1R, with razor blade of the YG8 that did not add rare-earth element, YT14, YW1, steel of turning spline axis, point of a knife suffers concussion, till till damaged of point of a knife. Classics for many times duplicate tests, before damaged of point of a knife, razor blade of YG8R, YT14R, YW1R can susceptive number of blows compares razor blade of YG8, YT14, YW1 to raise 1 ～ respectively 2 times above. The cutting force experiment of hard alloy uses rare land steel of 45# of turning of the YT14R of hard alloy razor blade that adds rare-earth element, YW1R (HB200) , as comparative as razor blade of YT14, YW1. With 3 measure power instrument to resistor type, measure and record 3 to cutting force: Advocate cutting force Fc, cut Fp of force of deep direction cutting, ff of force of feed direction cutting. Changing the condition of cutting parameter for many times, the statistical result that reach is: The Fc of razor blade of YT14R, YW1R, reduce than razor blade of YT14, YW1 respectively 5% the left and right sides, and their Fp and Ff reduce 10% ～ than razor blade of YT14, YW1 15% above. Advocate the experiment formula of cutting force is: Fc=2059ap0 of steel of YT14R turning 45# .

89f0.

Fc=2104ap0 of steel of 45# of 84N YT14 turning.

86f0.

Fc=1771ap0 of steel of 45# of 80N YW1R turning.

98f0.

Fc=2196ap1f0 of steel of 45# of 79N YW1 turning.

Consist in of rare-earth element of 87N cutting mechanism (W, ti)C or (W, ti, ta, in Nb)C solid solution, can aggrandizement horniness photograph; Can restrain WC grain inhomogenous grown, made incline to is even, average grain dimension is reduced somewhat. A few rare-earth element return solid dissolve to be in felt photograph Co, make felt photograph gets aggrandizement. Rare-earth element rich collect is reached in the place of phase boundary face of WC/Co (W, ti)C/(W, between the photograph interface such as Ti)C, often form the compound such as RE2O2 S with the chemical combination such as foreign matter S, O, improved the wetability that clean state improved appearance of felt of horniness get along with on the interface. From this, the concussion tenacity of hard alloy, bending strength reachs rare ground when the job fight concussion ability to get rising apparently. Its hardness, wearability and cutting tool apparently it is certain to fight the ability that diffuse and fights oxidation to also have rise. Check through electric lens, still discover rare tract hard alloy razor blade has rich cobaltic appearance in the surface layer when cutting, reason can be reduced cut the coefficient of friction between bits, workpiece and cutting tool, can reduce cutting force thereby. Rare-earth element is abounded in nature contain, the price is not high, in be being added in hard alloy, OK and apparent land increases function of mechanical, physics and performance characteristics, reason has wide applied perspective. Use example 1.

Factory of Beijing construction machinery uses YT14R and rod of steel of 45# of turning of YT14 hard alloy (shift is simple, hardness HB250) , cutting speed V=60m/min, cutting deepness Ap=0.

5mm, feed F=0.

51mm/r. The service life of YT14R raises 2 times than YT14, and already machined exterior quality to be improved somewhat 2.

Total factory uses Beijing internal-combustion engine YT14R and camshaft of 45# of turning of cutting tool of YT14 hard alloy (shift is simple, HRC28 ～ 32) , v=92m/min, ap=3mm, f=0.

6mm/r. YT14R can machine 80 ～ on average 100, and YT14 can machine 40 ～ only 50. And YT14R makes knife appearance little at YT14. 3.

Total factory uses Beijing internal-combustion engine YW1R and camshaft of 45# of turning of YW1 hard alloy (shift is simple, HRC28 ～ 32) , v=92m/min, ap=3mm, f=0.

6mm/r. YW1R can machine 60 ～ on average 70, without the phenomenon that hit a knife, and YW1 can machine 30 ～ only 32, and hit a knife sometimes. 4.

Head office of Chinese spaceflight industry the 502nd institute uses 5 courtyards YW1R and Sb=0 of 　 of tensile strength of 1Cr18Ni9Ti(of stainless steel of turning of YW1 cutting tool.

55GPa) and GH3128(sb=0 of high temperature alloy.

84GPa) , v=30 ～ 60m/min, ap=0.

7 ～ 1.

5mm, f=0.

08mm/r. The service life of YW1R is the 2 times above of YW1, the treatment surface surface roughness of YW1 is Ra=3.

2mm, YW1R is Ra=1.

6mm. 5.

Factory of the first machine tool uses Beijing YG8R and 180) of ～ of HB170 of hardness of HT200(of casting pig of turning of YG8 hard alloy, v=80m/min, ap=2mm, f=0.

3mm/r. 1 what the service life of YG8R is YG8.

5 ～ 2 times, and anti-impact properties is improved somewhat. CNC Milling