Open Surface Pores Research Articles

Austenitic Nitriding and Bainitic Hardening of Sintered Irons

AbstractA dry thermochemical treatment cycle has been optimized for a range of densities of sintered plain-iron powder samples. The process involves the formation of iron-nitrogen austenite, by using an ammonia hydrogen atmosphere, and its isothermal decomposition to bainite. Nitriding is shown to follow the parabolic rate law and the relationship between case depth and treatment time has been established for a range of sintered densities. Surface condition has a great effect on the nitriding kinetics, as-sintered compacts with an open pore surface structure reacting much more quickly than those which have been ground so that the surface has been smeared and closed. Improved mechanical properties are developed in the treated samples with hardnesses of up to 550 HV being achieved.

Mechanical anchoring of polymer layers on polymer substrates with an open‐porous surface structure

Mechanical anchoring of polymer layers on polymer substrates with an open‐porous surface structure