Economic net-shape forming of TiAl alloys for automotive parts

Alpha-case formations between investment molds and TiAl alloys were investigated for the economic TiAl alloys net-shape forming. In the case of TiAl alloys, there were no α-case formation reactions. There were neither interstitial nor substitutional α-case formations since TiAl alloys have both negligible solubility of oxygen and low activity in molten states. The fluidity of TiAl alloys is increased with mold preheating temperature since they have a peritectic reaction that appears in the form of envelopment, surrounding each particles of the primary constituent. The results of the investment casting of TiAl alloys confirm that the casting route in our study can be an effective approach for the economic net-shape forming of TiAl alloys.