Microsturctural variation in Al-Cu-Y Sysytem Under Metastable condition

Abstract

This dissertation deals with the microstructural variations and indentation characteristics of AI-Cu- Y alloys. The aim of the present work is to study the changes in microstructure. The alloy ingots obtained after melting the constituent clements were cast under metastable conditions. High energy ball milling of copper rich composition is carried out at five different time intervals for two different balls to powder ratios (BPR). In Chapter I, a brief description of relevant portion of phase diagrams is given. The effect of undercooling and flux additions 011 alloy compositions is also discussed. Important of high energy ball milling is also presented. In Chapter 2, the melting procedure and method of characterization of as cast metastable and milled samples is given. Chapter 3 outlines the results of the present investigation. The results of the Metallography, DTA, XRD and Micro hardness are presented and discussed. The phase transformation behavior of copper rich alloys by high energy ball milling is also presented. Chapter 4 summarizes various conclusions arrived at based on the present study and closes with the scope of future work. The references are given at the end of dissertation. The details of relevant PDF file from ICDD software are given in appendices.