Of Wc-co Composite Powders And Alloys Developed

In this paper,the history and technological process of cemented carbide are briefly introduced.Then the conventional producing technology and the latest development of cemented carbide are reviewed.Finally,metal coating ceramic composite powder is briefly introduced.In this paper,the method of Solution-chemistry and hydrogen reduction process is used to produce WC-Co composite powder.The main factors which affect WC-Co composite powder are obtained by plenty of experiments and analysis,and the mechanism of reduction process is discussed.The best factor level which affects WC-Co composite powder is obtained by factorial and optimization experiments.In this research,MINITAB 14 is used to analyze main effects for factors,and the uniformity and microstructure of powders are investigated by means of SEM.Compositing analysis instrument test Ctotal,cbc,O and Co of WC-Co composite powder.Futhermore,the range of reducing temperature for WC-Co composite powder is tested by means of TG/DSC. Experimental evidence indicates that the best factor level is confirmed,which,the value of TEA is 0.4 mol TEA per one mol Co,without sucrose,and the first strap temperature is 300 degree,and the second strap temperature is 400 degree,and the third strap temperature is 650 degree,meanwhile,the velocity of graphite boat which is pushed is 60 minutes per two boats.Based on this new method,the particle is more homogeneous than the conventional method.Meanwhile,it avoids milling process,and it offers a new technics to produce WC-Co powder.In this paper,YG6 cemented carbide is produced by this new producing method,and its mechanical properties are analysed, then they are compared to YG6 cemented carbide produced by the conventional producing method.In this research,powder granularity are investigated by means of laser granularity instrument,and the phase are tested by means of XRD.Futhermore,the microstructure and mechanical properties are tested by means of SEM,electronic tensile testing machine and hardness machine.The sintering process and mechanism of cemented carbide is analysed.Experimental evidence indicates that the distribution of Co-phase of WC-Co cemented carbide produced by the new method is more uniformitily than WC-Co cemented carbide produced by the conventional method. YG6 cemented carbide produced by the new method,which,the value of its density is 14.99 gram per stere,and the value of its hardness is 90.0 HRA,and the value of its fracture strength is 1450 MPa,and the value of relative magnetic saturation is 83.5 percent.Also,ηphase and pores result in the degression of mechanics properties of cemented carbide,especially, damage fracture strength.WC-Co composite powder produced by the new method is too hard,which results in pores formed. So,on the premise that the hydrogen reduction is completed adequately in the process of hydrogen reduction.The more lower the reducing temperature is,the more the better.