Impact Resistance of Commercially Applied TiAl Alloys and Simple-Composition TiAl Alloys at Various Temperatures

Abstract

For currently used TiAl alloys, the impact resistance is a critically important property that determines their suitability for use, especially in settings when continuous use under harsh conditions is necessary. However, there are almost no examples of the investigation of the impact resistance of these alloys at realistic temperatures. Therefore, in this study, the impact resistance from room temperature to 1000 °C of various cast and forged TiAl alloys proposed to date or still in commercial use, as well as simple composition TiAl alloys and Inconel 713C—a commonly used material—were evaluated using the Charpy impact test, which is the simplest and most realistic way to evaluate industrial impact resistance. It was found that the TiAl alloys underwent brittle fracturing, even at high temperatures, and had significantly lower impact resistances than Inconel 713C. In addition, the impact resistances of all commercial TiAl alloys were inferior to those of the binary alloys, and those of the TiAl4822 and TNM alloy were not significantly different. Crucially, it was found that ternary alloys containing Cr or V had much better impact resistance than the commercial and binary TiAl alloys.

Keywords

• cast TiAl alloy
• forged TiAl alloy
• additive element
• charpy impact test
• turbine blade
• inconel 713C