The Effect of Temperature on the Impact Behavior of TiB2 Reinforced XDTM-TiAl Intermetallic Matrix Composites
Abstract
A study was performed to determine the effect of temperature on the impact behavior of two XD(TM) processed TiB2 reinforced TiAl intermetallic composites (IMC's). An existing instrumented tup drop tower apparatus was modified for the program. The IMC compositions were Ti-49 at % Al + 5 vol. % TiB2 and Ti-48 at % Al + 10 vol. % TiB2. The specimens were notched to an a/w ratio of 0.2. Details and test procedures for the modified apparatus were presented. Test temperatures ranged from -192 deg C to 1100 deg C. Impact toughness and maximum bending stress for both IMC's decreased from room temperature to temperatures as high as 1100 deg C. An important experimental observation which supports these results is the change from transgranular cleavage to intergranular fracture at the 760 deg C test temperature. Also noted is the possible contribution to decreasing toughness of unfavorable difference in coefficient of thermal expansion between TiB2 and the matrix with increasing temperature. Data repeatability and verification of the ability to observe high temperature brittle-to ductile transition behavior established confidence in the modification of the existing instrumented tup apparatus.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1992
- Accession Number
- ADA262924
Entities
People
- D. F. Hasson
- M. K. Hamm