Paper number 512

A GENERAL APPROACH TO THE MEASUREMENT OF THERMAL RESIDUAL STRAINS AND STRESSES IN SICW/AL COMPOSITES

Q. Y. Liu¹,² W. D. Fei²

1LNM, Institute of Mechanics, Chinese Academy of Sciences,
Beijing 100080, P. R. China
2School of materials science and engineering, Harbin Institute of Technology,
Harbin 150001, P. R. China

Summary

On changing temperature, traditional macrostress and microstress as well as thermal mismatch stress will exist in SiCw/Al composites, thermal mismatch stress was emphasized on in this paper. Firstly, thermal mismatch stresses-strains in a single SiC whisker were analyzed; and then effects of thermal mismatch stress on the position of X-ray diffraction peak were discussed, the relationship between thermal residual strains and the shift of diffraction peak was established. On the basis of the above discussion, considered the special crystallographic characteristics of SiC whisker, a new measurement method of thermal mismatch stress was developed by measuring the lattice distortion of SiC whisker. Thermal mismatch stresses in SiCw/Al composites were calculated, and the results agreed well with the previous research works.

Keywords

SiCw/Al composites, thermal residual strains and stresses, X-ray diffraction.