PROCESSING OF INTERMETALLIC COMPOUNDS FOR STRUCTURAL APPLICATIONS AT HIGH-TEMPERATURE

The establishment of secondary processing methods is essential to enab le the use of intermetallic compounds for structural applications at h igh temperature. Of the many processing methods, joining and surface m odification techniques were examined in this work. Joining of TiAl was accomplished by laser welding without the formation of hard, metastab le alpha(2)-phase. Joining was also achieved by the application of SHS (self-propagating high temperature synthesis) reaction. For the forma tion of a layer of intermetallic compound on a metal surface, the proc essing method must be selected according to the desired thickness of s urface layer. Laser cladding and laser alloying were found to be reaso nable techniques to obtain a layer thickness up to 1 mm, whereas spray ing and SHS bonding methods were found to be effective for thicknesses of 1-2 mm and > 2 mm, respectively. The production of intermetallic m atrix composite materials was found to be attainable by these methods. Copyright (C) 1996 Elsevier Science Ltd