Effect of porosity on the size of surface microirregularities in the finish lathe-turning and smoothing of sintered materials

Conclusions

The greatest influence on surface roughness in the lathe-turning of P/M materials is exerted by the ductility properties of the materials. The effect of this factor in lathe-machining is greater with P/M than with similar dense materials. The mechanism of the influence of porosity on the surface roughness and service properties of parts made of P/M materials is very complex, and should, in the author's opinion, be the subject of a special investigation. Smoothing not only strengthens the surface layer of a part made of a P/M material, but also consolidates it, i.e, increases its density, and this in turn improves the operating characteristics of the part. In finish lathe-turning and smoothing, to each class of P/M material there corresponds a certain tool material which enables the best-quality machined surface to be obtained.