Research For The High Entropy Alloys Bond Of Diamond Abrasive Tools

High entropy alloys?HEA?used as based binder can replace traditional metal binder which was used to bind diamond abrasive,so that this diamond tools can be used at higer temperature and linear velocity.The high entropy alloys,calculated by different formuals,was optimized and designed by Spark Plasma Sintering?SPS?.In order to obtain new superhard tools which have high strength,high hardness,and high thermostability,copper tin alloy and aluminum powder sintering additives mixed with appropriate diamond were added in the process of hot-pressing sintering.High entropy alloys which contains Fe,Co,Ni,Cu,Zn,Al,Mn of five to seven kinds of elements was prepared by mechanical alloying.The high entropy alloys presents simple solid solution structure of FCC and BCC.AlFeCoNiCu denotes the high entropy alloy with five principal elements,AlFeCoNiCuZn denotes the high entropy alloy with six principal elements,Al FeCoNiCuZnMn denotes the high entropy alloy with seven principal elements.With the increase of number of principal component,the sintering temperature is reducing.Compared with AlFeCoNiCu and AlFeCoNiCuZn,AlFeCoNiCuZnMn,the bending strength and hardness of which are 460 MPa and 376 HV respectively,has lower sintering temperature of 935 °C when applying Spark Plasma Sintering,while Al FeCo NiCu has the bending strength and hardness of 654 MPa and 528 HV at the temperature of 1125 °C.With the increase of Al and Zn,the temperature of the high entropy alloys is gradually reducing.Excessive Zn weakened the bending strength and hardness of high entropy alloys.It is mainly because of the “cocktail effect” of high entropy alloys and the lattice distortion caused by mechanical alloying.The high entropy alloys of Al_1.5CoNiFeCuZn MnY_0.1 and Al_1.5CoNiFeCuZnY_0.1,sintered at 900 °C by hot pressing sintering,add 20% mass fraction of aluminum powder,the bending strength of which significantly increased,reaching are 460 MPa and 450 MPa,respectively,both of which sintered with diamond abrasive of 10 ?m in size and concentration of diamond abrasive is 40%,60% and 80%.The wettability of them is poor.Besides,the bending strength decreased with the increase of diamond concentration.When the diamond concentration is 40%,T1103 A and T1103 B have the highest bending strength which are 316 MPa and 234 MPa,respectively.The high entropy alloys of Al_1.5NiSnCuZnMn,Al_1.5NiSnCuZn,Al_1.5NiSn_0.5CuZnMn and Al_1.5NiSn_0.5CuZn which contains the elements of Ni,Cu,Zn,Al,Mn and Sn were prepared by mechanical alloying.They have lower sintering temperature.Overadded Sn formed part of the alloy in the process of mechanical alloying.The high entropy alloys of NiSn_0.5CuMn,spark plasma sintering at 680 °C,has the highest bending strength and hardness which are 418 MPa and 583 HV.