Surface Finish

The overall finish and surface reflectivity of PM materials depends on density, tool condition and secondary operations. Conventional profilometer readings give an erroneous impression of surface finish because a different surface condition exists from that found on the machined or ground surfaces of wrought materials. Conventional readings take into account the peaks and valleys of machined surfaces, while PM parts have a series of very smooth surfaces that are interrupted with varying sized pores.

Effective surface smoothness of PM components compares favorably with ground or ground and polished surfaces of wrought and cast components. Surface finish can be improved further by secondary operations such as repressing, honing, burnishing or grinding. The surface finish requirements and methods of determination must be established by mutual agreement between purchaser and producer, considering end use of the part.