Machining: Sintered parts do have some porosity and it is, therefore, necessary to differentiate their machining behaviour from those of fully dense wrought products. The major differences are, as follows: (i) when a porous metal is machined, the depth of work hardening is more important than for the wrought metal, as in case of former, pores create stress concentration. (ii) The temperature at the tool end causes oxidation of the pore surface. (iii) The surface porosity enhances tool vibra...
