| Artificial diamond has been widely used in various industries due to its ultra-high hardness,high strength,and good wear resistance.However,artificial diamond is extremely brittle,chipping probably occurs when it is used as a cutting tool,which limits the application in the field of cutting.Recently,with the occurrence of metal matrix composite materials,a new material made of brass and steel has been developed,this material has high conductivity,good ductility,and high strength,which overcomes the shortcomings of artificial diamond,so it can be used to manufacture cutting tools.In this paper,the diamond particles with 200～250μm,copper powder,zinc powder,and iron powder were employed to prepare copper reinforced by artificial diamond/iron sandwich composites(AD/Cu-Fe sandwich composites)that can be used for stone cutting by powder metallurgy.According to the melting point of the copper matrix,the effect of sintering temperature on the mechanical properties and microstructure of AD/Cu-Fe sandwich composites was investigated under the sintering temperatures of 740℃,750℃,760℃,770℃,and 780℃.An AD/Cu-Fe sandwich composite with the same structure prepared by different processes was taken as the control sample,and the purpose of this study is achieving the AD/Cu-Fe sandwich composites with better performance by adjusting the sintering temperature.The microstructure morphology,element distribution and composition of AD/Cu-Fe sandwich composites were characterized using SEM,EDS,XRD.The following conclusions can be drawn:(1)When sintering temperature is between 740℃～780℃,the graphitization of diamond particles is not obvious.After milling and mixing,the distribution of artificial diamond particles is more uniform,and a good interface is formed between the artificial diamond and copper matrix.(2)The density and relative density of the AD/Cu-Fe sandwich composite prepared at770℃are highest(7.114 g/cm~3)and the density(94.9%),which are improved by6.4%compared with the control group.(3)Because the AD/Cu-Fe sandwich composite takes iron as the transition layer metal,it has a good bending strength.When sintering temperature is 770℃,the bending strength of the AD/Cu-Fe sandwich composite reaches 1076 MPa,which is1.2 times of that of the control group.(4)The results of wear test show that the wear resistance and hardness of AD/Cu-Fe sandwich composites increase first and then decrease with increasing sintering temperature from 740℃to 780℃.The best wear resistance of the composite prepared at 770℃is 4.2 times that of the control sample. |
PDF Full Text Request