Ultrahigh temperature tensile properties of arc-melted tungsten and tungsten-iridium alloys

Tungsten is one of the most important metals for high temperature applications. The major deterrents to the use of tungsten are poor fabricability at room temperature and rapid decrease in strength at temperatures above 1600 K. Previous investigations have shown that the addition of rhenium to tungsten improves both room- temperature fabricability and high-temperature strength. Based on its similarity to rhenium's electron structure, iridium as another potential alloying element in tungsten. It was recently confirmed that tungsten-iridium alloys with less than 1.0w/o iridium exhibit better fabricability than tungsten-rhenium alloys at room temperature. The strength properties of tungsten-iridium alloys at ultrahigh temperatures have not yet been researched. The present paper reports the tensile properties of dilute tungsten-iridium alloys in the temperature range 1600 to 2600 K. The focus of the present paper is to examine the effects of iridium concentration and test temperature on the strength and fracture behavior of tungsten-iridium alloys at ultrahigh temperatures