Enhancement the Microstructure and Mechanical Properties for Pb-Sn-Sb Alloys by Using Equal Channel Angular Extrusion

Abstract

This study aims to enhance the compression strength in one type of Pb-Sn-Sb alloys which wellknown by (Babbitt-ASTM B23 Alloy 13). The ‎processing doing via equal channel angular extrusion technique. Three casting were implemented to ‎manufacture the alloy; Chill Casting (CC), New Rheocasting (NRC) and Gravity Die Casting (GDC). The ‎microscope examination shows that the microstructures contain two phases, α-Pb and cubic shaped ‎intermetallic compound (β-SbSn) in a matrix of ternary phases. CC was fine equiaxed as well as NRC, while ‎in GDC was a dendrite α-Pb phase with remaining β-SbSn phase as a cubic shape. Higher mechanical properties in compression were recorded for Gravity die casting (12.7 %) while the NRC registered the highest value in yield strength (11.7 %). On the other hand, the casting techniques had a slight difference in Young's modulus. The other resulted data like hardness showed that NRC is the first reading (12.55 %) and then gravity casting recorded as second score comparing with other (11.79 %), The results ‎showed aslo that increasing forming temperature during angular extrusion has an adverse effect on compression ‎strength. The study ‎concluded that microstructural change caused by ECAP softens the material due to the break-up the original ‎precipitate and accelerate from the dynamic recrystallization.