For plastic deformed parts, the dimensional accuracy is significantly affected by residual stresses and so does the performance in service. Therefore, the rolling process of GH4169 alloy sheet at room temperature was investigated by finite element method. The effects of rolling reduction, friction coefficient, rolling velocity and initial stress on the longitudinal residual stress distribution over the thickness of GH4169 alloy sheet were analyzed. The results show that the values of longitudinal residual stress can be slightly reduced by increasing the rolling reduction and velocity. The longitudinal residual stress over the thickness distributes as “V” type or weak “W” type. The initial stress mainly has an effect on the longitudinal stress in the backward slip area. But the friction coefficient has remarkable influence on longitudinal residual stress. With the friction coefficient increasing from 0.1 to 0.5, the value of longitudinal residual stress on the sheet surface is reduced by 282 MPa. Simultaneously, the tensile stress turns into compressive stress with a strong “W” type distribution.

The healing behavior of micropores in powder metallurgy (P/M) 316L stainless steel during hot forging and subsequent heat treatment was studied. The results showed that hot forging can improve the homogeneity of the pore size and enhance the relative density of material in varying degree due to different forging temperatures. As a result of deformation and diffusion bonding at high temperature, the irregular pores were spheroidized and finally turned into stable inner grain pores. The comparison of compression behavior between P/M and wrought dense materials has shown that the pores can either be the obstacles of dislocation movement or be the nucleation sites accelerating the recrystallization according to the difference of deformation temperatures.

A finite element analysis (FEA) model to analyze imprint of a bulk metallic glass (BMG) in the temperature range near the glass transition temperature (Tg) has been developed. The material model includes both Newtonian and non-Newtonian flow behavior. The results reveal that the topology of the imprinted surface depends strongly on temperatures, but only mildly on surface feature scale. As a result of the flow characteristics of BMG in the temperature range above Tg, the lubrication condition has only a slight effect on BMG imprinting.