Influence of Frictional Constraints between the Combined Stresses and the Continued Deformation and Densification of Sintered High Carbon P/M Steel during Cold Deformation

摘要

Powder metallurgy processes features some potential advantages over ingot metallurgy (I/M) processes. Using the secondary deformation process such as powder forging, rolling, extrusion etc., the near net shape product can be achieved, which avoids expensive machining and finishing operations unlike in I/M processes. Therefore, the present investigation pertains to develop experimental data during cold axial deformation under three different lubricant constraints for the eutectoid steel composition of constant aspect ratio of 0.75. Deformation and dimensional measurements were carried out at the end of each step of loading. Plots were drawn between stresses with deformations and densification, which resembles like a typical creep curve. The first and third stage shows steep rise, which offers resistance to deformation, whereas the second stage shows virtually steady state, deformation needed gradual increase in applied stresses but with high rate of densification. Further, the lubricant employed facilitated the deformation compared to nil lubrication condition