Fabrication of an r-Al_2Ti intermetallic matrix composite reinforced with α-Al_2O_3 ceramic by discontinuous mechanical milling for thermite reaction

摘要

In this study, a powder mixture with an Al/TiO2 molar ratio of 10/3 was used to form an r-Al2 Ti intermetallic matrix composite(IMC) reinforced with α-Al2O3 ceramic by a novel milling technique, called discontinuous mechanical milling(DMM) instead of milling and ignition of the produced thermite. The results of energy dispersive X-ray spectroscopy(EDX) and X-ray diffraction(XRD) of samples with varying milling time indicate that this fabrication process requires considerable mechanical energy. It is shown that Al2Ti–Al2O3 IMC with small grain size was produced by DMM after 15 h of ball milling. Peaks for γ-TiAl as well as Al2 Ti and Al2O3 are observed in XRD patterns after DMM followed by heat treatment. The microhardness of the DMM-treated composite produced after heat treatment was higher than Hv 700.