Design and Fabrication of High Strength, High Modulus Polymer Reinforced Metal Matrix Composites for Light Weight Applications

Abstract

Objectives: The present work reports the possible solution of using the high thermal stability polymer fibres with superior mechanical properties as that of, or, even better than metals for light weight applications like aerospace and automobile. Methods/Statistical Analysis: The PBO filament fibre was used as reinforcement. The PBO fibres were electroless copper coated to protect the polymer fibre from oxidation during processing and to improve the interfacial properties between the reinforcing polymer and the metal matrix. LM6 aluminium cast alloy was used as a matrix metal. The electroless copper coated PBO fibres preform were unidirectional placed inside a mould and infiltrated by molten liquid metal. Findings: After casting, it was found that the liquid melt could infiltrate only partially through the first layer of the fibre preform, and could not infiltrate further, which was evident from the infiltrated metal front. This was mainly because of the forced convective heat transfer made by the argon cover gas, which cools the molten metal front and thereby increases the surface tension of the advancing front. It was further noticed that some charring of the polymer fibres after two hours of casting, which reflects that, there was oxidation of polymer fibres after prolonged heating by the hot infiltrating metal front in absence of argon cover gas after first one hour of its use after casting. Application: The new material proposed for development could find applications in light weight high performance vehicles like aerospace and automobiles..