METHODS FOR HEAT TREATING AND MANUFACTURING A THERMOMECHANICAL PART MADE OF A TITANIUM ALLOY, AND THERMOMECHANICAL PART RESULTING FROM THESE METHODS

摘要

The invention relates to a method for heat treating a thermomechanical part made of a TA6Zr4DE titanium alloy. Characteristically, a solutionizing step is performed at a temperature of between ß transus -20 °C and ß transus -15 °C for a duration of 4 to 8 hours with a cooling rate at the end of the treatment of greater than 200°C/min. The part produced has a fine microstructure made up of short alpha phase needle groups and has thus has improved resistance to creep under stress at low temperature ("dwell fatigue"). The method is advantageously finished by returning to 595°C for 8h. Of application in production of high-pressure compressor wheels for a turbine.