Influence of Silicon Additions on Microstructure and Mechanical Properties of Manganese Bronze Alloys

The present investigation aims to synthesize RB۰۳۱, RB۰۳۲ manganese bronze alloys equivalent to HTB۱ and HTB۲ alloys  with additions of silicon  and to characterize them with the help of Microstructure and Mechanical properties. The methodology involves  melting of alloy’s in a ۳۰۰kg Coreless medium frequency induction furnace, casting them in Permanent and Shell moulds with optimum values of Zinc equivalent and retaining their high mechanical properties. The study includes the development and mechanical property measurements of the alloys synthesized. Characterization has been carried out using Optical Microscopy and Scanning Electron Microscopy with EDAX analysis for investiagtion of compositional variations and inquisition of hardness measurement & tensile properties. It is concluded from this work that RB۰۳۲ alloy cast in Permanent moulds has superior hardness and tensile properties compared to Shell moulds and far exceeds that of NAB (AB۲) alloys processed under similar conditions. Further, this investigation includes grain refinement by suitable Heat treatment studies to combat Hot Tearing since the strength is adequate enough with RB۰۳۲ exhibiting higher hardness than other two alloys.

Keywords:

Zinc equivalent (ZE) , Alpha + Beta Phase (α+ β) , Hot tearing , Permanent Mould , Shell Mould , Si:Mn ratio , Manganese silicides