Effect of Sintering Temperature and the Content of Nanoscale Tungsten Carbide on the Mechanical Properties of Polycarbide based Hard Alloys

摘要

This paper presents an investigation on the effect of alloying tungsten nano-carbideand the sintering temperature on the mechanical properties of alloys of the TiC-5VC-18NiCr systemwith Ni:Cr = 3:1, using design of experiments methods. The alloys were produced by the powdermetallurgy route, which included technological operations of mixture homogenization, uniaxial coldpressing and vacuum sintering. Eleven impact factors were found and they were fixed at a certainlevel. The variation factors were the following: the sintering temperature in the range of 1300-1400 ℃and the content of alloying tungsten nano-carbide in the range of 5-15 % (wt). The Vickers hardness,the fracture toughness and the bending strength were the parameters of optimization. On the basis ofthe analysis of the obtained regression equations and the constructed response surfaces the optimalvalues of the variation parameters, which provided maximum values of the studied characteristicswere found.