Evaluation of Ti-48al-2cr-2nb Under Fretting Conditions

Download or read book Evaluation of Ti-48al-2cr-2nb Under Fretting Conditions written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-03 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fretting behavior of Ti-48Al-2Cr-2Nb (y-TiAl) in contact with the nickel-base superalloy 718 was examined in air at temperatures from 296 to 823 K (23 to 550 C). The interfacial adhesive bonds between Ti-48Al-2Cr-2Nb and superalloy 718 were generally stronger than the cohesive bonds within Ti-48Al-2Cr-2Nb. The failed Ti-48Al-2Cr-2Nb debris subsequently transferred to the superalloy 718. In reference experiments conducted with Ti-6Al-4V against superalloy 718 under identical fretting conditions, the degree of transfer was greater for Ti-6A1-4V than for Ti-48Al-2Cr-2Nb. Wear of Ti-48Al-2Cr-2Nb generally decreased with increasing fretting frequency. The increasing rate of oxidation at elevated temperatures led to a drop in wear at 473 K. However, fretting wear increased as the temperature was increased from 473 to 823 K. At 723 and 823 K, oxide film disruption generated cracks, loose wear debris, and pits on the Ti-48Al-2Cr-2Nb wear surface. Both increasing slip amplitude and increasing load tended to produce more metallic wear debris, causing severe abrasive wear in the contacting metals. Miyoshi, Kazuhisa and Lerch, Bradley A. and Draper, Susan L. and Raj, Sai V. Glenn Research Center NASA/TM-2001-211205, NAS 1.15:211205, ASTM-STP-1425, E-13006-1