In the modern mechanical , as well as the material of the cemented carbide and HSS is most often used , almost equally . BACKGROUND OF THE INVENTION 1 . Field of the Invention and Application of High - Speed Steel , existing for over a century of history , the cemented carbide is nearly half a century ago . But both of them developed many new varieties , and its ever increasing performance , In machining plays an important role . Addition of Rare - earth carbide is one of the varieties . rare - earth element is the element in the Periodic Table having an atomic number of 57 to 71 ( from La to Lu ) , plus 21 and 39 ( Sc and Y ) , a total of 17 elements is exhibited . Certain rare - earth element , in a manner where , however , it has been added to the conventional cemented carbide , is effective to improve their mechanical properties and machinability . China ' s resource - rich rare - earth element , rare - earth alloy of research and development , ahead of other countries . have been developed in the following grades of cemented carbide tool with rare earth : YG8R ISOK30 ( equivalent ) level , YG6R ( K20 ) , YW1R ( M10 ) , YW2R ( M20 ) , of the Integrate Performance , YT14R ( P20 ) , YT15R ( P10 ) , YS25R ( P25 ) . And mine , geology YG11CR tool mark . The above - described P - type and M type , K type rare - earth alloy cutting performance are studied in experiments , and the activity of the cutting mechanism .

rare - earth alloy mechanical properties

YG8 , YT14 ) , YW1 horniness alloy added with Ce as rare - earth element , rare - earth alloy YG8R , YT14R , YW1R . YG8R is mainly used for rough machining of cast iron and nonferrous metals ; YT14R main steel material for an intermediate finishing ; YW1R is as a general - purpose grade can be used for a variety of workpiece material of the semi - finishing .

After the test , after the rare earth elements are added to cemented carbides was dense ; room - temperature hardness and high - temperature hardness , such as the improvement of fracture toughness and flexural strength were significantly improved , respectively , is increased by 20 % and 10 % or more .

rare - earth alloy to improve the wear and service life test

Through the test we know , with no rare - earth element as compared to the original blade , YG8R , YT14R , YW1R blade wear and service life are increased to different degrees .

We also made a rare impact test YG8R , YT14R , YW1R et al ) addition of a cemented carbide insert , with the rare earth alloy YG8 , YT14 ) , YW1 , turnery splined shaft , the tip , until the tip chipping . The repeat test , tool tip breakage before YG8R , YT14R , YW1R blade to be able to withstand the impact of the number of times respectively compared with YG8 , YT14 , YW1 blade was 1 ~ 2 times or more .

rare - earth alloy cutting experiment

The rare earth elements are added to a cemented carbide insert YT14R , YW1R turning 45 # steel , HB200 ( ) , the YT14 , YW1 blade . triaxial resistance dynamometer , for measuring and recording the three - way cutting force : the main cutting force Fc , the cutting direction the cutting force Fp , in the direction of feed of the cutting force Ff . In a number of times , the area of the cutting parameters , and come to the conclusion that the statistical results are : YT14R , YW1R blade of Fc ) compared to that of YT14 , YW1 blade is decreased by about 5 per cent of their Fp and Ff is than YT14 , YW1 reduced blade 10 % ~ 15 % or more .

main cutting force formula is :

YT14R turning 45 # steel Fc = 2059ap0 . 89f0 . 84N .

YT14 turning 45 # steel Fc = 2104ap0 . 86f0 . 80N

YW1R turning 45 # steel Fc = 1771ap0 . 98f0 . the

YW1 turning 45 # steel Fc = 2196ap1f0 . 87N

Cutting Mechanism

rare - earth element is present ( W , Ti ) C or ( W , Ti , Ta , Nb ) C solid solution in , or to strengthen a hard phase and were able to inhibit the WC grain size of the holding nail 91 toward the uniform , the average grain size is reduced . a small amount of rare - earth element is also dissolved in the binder phase is promoted . The geochemistry of the WC / Co phase at the interface and ( W , Ti ) C / ( W , Ti ) C and the like between the adhesion interfaces , often with impurity is S , O etc . are combined to form a compound such as re2o2s , which improved on the clean condition and improves the wettability of the hard phase and binder phase . Thus , the rare - earth alloy impact toughness , flexural strength and shock resistance is remarkably improved . its hardness , wear resistance and the tool on the surface of the diffusion and oxidation resistant ability is also raised to a certain degree .

Through SEM test , also found in rare - earth alloy blade during the cutting of the surface of cobalt - rich phenomenon , so as to be capable of decreasing the chip , the friction coefficient between a workpiece and a tool , thereby it is possible to reduce the cutting force .

Rare in nature - rich , low cost and high adde in cemented carbides can significantly improve the mechanical and physical properties , and has wide application prospect .

Application Examples

1 . Construction Machinery and The YT14R YT14 cemented carbide turning shaft 45 # steel ( quenched and tempered hardness HB250 ) , the cutting speed v = 60 m / min , depth of cut ap = 0.5 mm , feed f = 0.15 mm / r . YT14R of YT14 , The service life is increased two times , and that the surface quality improved slightly

2 . Beijing adopts YT14R Iternal - combustion Engine Factory and YT14 cemented carbide milling cutter turning camshaft ( quenched and tempered 45 # , HRC28 ~ 32 ) , v = 92m / min , ap = 3 mm , f = 0 . 6mm / r . YT14R average machining can be 80 to 100 members , while only 40 ~ 50 YT14 processing member . YT14R and chin did less than YT14 .

3 . Beijing Internal - combustion Engine General Factory for Cemented Carbide YW1 YW1R and turning of the camshaft ( 45 # quenched and tempered , HRC28 ~ 32 ) , v = 92m / min , ap = 3 mm , f = 0 . 6mm / r . YW1R average can process 60 to 70 pieces , no chin , YW1 only can process 30 to 32 , and is sometimes called the knife .

4 . China Aerospace Corporation ( Section 502 of the five branches of the institute and YW1R YW1 turning stainless steel 1Cr18Ni9Ti sb = 0 ( the tensile strength of 25.52MPa ) and high temperature alloy GH3128 ( sb = 0 . 84GPa ) , v = 30 ~ 60 m / min , ap = 0 . 7 ~ 1 . 5 mm , f = 0.08 mm / r . YW1R service life is 2 times or more of YW1 , YW1 of machining surface roughness of Ra = 3.2 mm , YW1R Ra = 1.6 mm .

5 . Beijing No.1 Machine for Turning and YG8R cemented carbide YG8 Gray Cast HT200 HB170 ~ 180 ( hardness ) , v = 80 m / min , ap = 2 mm , f = 0.3 mm / r . YG8R life of YG8 of 1.5 to 2 times , and improved impact resistance .