Fabrication of TiB2-Al1050 Composites with Improved Microstructural and Mechanical Properties by a Liquid Pressing Infiltration Process

Abstract

This study was conducted on titanium diboride (TiB2) reinforced Al metal matrix composites (MMCs) with improved properties using a TiB2 and aluminum (Al) 1050 alloy. Al composites reinforced with fine TiB2 at volume ratios of more than 60% were successfully fabricated via the liquid pressing infiltration (LPI) process, which can be used to apply gas pressure at a high temperature. The microstructure of the TiB2-Al composite fabricated at 1000 °C with pressurization of 10 bar for 1 h showed that molten Al effectively infiltrated into the high volume-fraction TiB2 preform due to the improved wettability and external gas pressurization. In addition, the interface of TiB2 and Al not only had no cracks or pores but also had no brittle intermetallic compounds. In conclusion, TiB2-Al composite, which has a sound microstructure without defects, has improved mechanical properties, such as hardness and strength, due to effective load transfer from the Al matrix to the fine TiB2 reinforcement.