Influence of powder properties on compressibility of prealloyed atomised powders

Abstract

The compressibility of metal powders depends on many factors, including morphological and mechanical properties of particles. Alloying elements increasing ferrite solid solution strengthening can influence the compressibility of prealloyed steel powders. The contribution deals with compressibility of Fe–Mn–Cr–[Mo–Ni] prealloyed and premixed powders with total alloying ∼2·0%. Quantification of powders compaction was performed using equation P=P ₀exp (−Kp¹¹); proposed by Parilak et al. (1994), where P is the porosity at pressure p; P ₀ is apparent porosity; K and n are parameters related to morphology and plasticity of powder particles. The equation enables to study the compressibility in relation to geometry and mechanical properties of powder particles, through development of K and n parameters on pressing pressure p. The tested powders exhibited low varieties in the density at pressing pressures higher than ∼400 MPa, but some differences were identified during the first stage of compaction, at pressing pressures up to ∼200 MPa.

Keywords:

• PREALLOYED POWDERS
• COMPRESSIBILITY
• GEOMETRIC STRENGTHENING
• VOLUME PLASTIC DEFORMATION