Abstract.A three 3D transient finite element model has been developed to predict the temperature distribution in Ti6Al4V alloy plate workpiece. It is found that the temperature profile is strongly dependent on the parameters of the laser beam and material properties. Also the thermal model results were compared with results produced by experimental work and these show close agreement.

A 3D finite element model of the machining of Ti6Al4V alloy has been developed. This model is able to simulate the formation of continuous or discontinuous chips during the cutting process that depends on the cutting conditions. In this model, the yield stress is considered as a function of the strain, the strain rate and the temperature. The dynamic effects, thermo-mechanical coupling, constitutive damage law and contact friction are taken into account. The stresses and temperature fields, chip formation and tool forces are obtained at different stages of the cutting process.

Plasma arc was used as a heat source to make a surface quenching on alloy cast iron, and orthogonal test was used to optimize the surface hardening technological parameter of plasma arc. The influence of the technological parameters on hardness and depth of the hardening layer was analyzed, and the microhardness and the microscopic structure condition after being disposed were also analyzed and discussed.