一方向およびアングル・プライSiC繊維-Al合金の熱膨張

抄録

The linear thermal expansion of unidirectional and angle plied silicon-carbide fiber-reinforced aluminum alloys was measured as functions of fiber and plying angles. These composites were prepared by a squeeze casting method, and pure Al and an Al-4.5%Cu alloy were used as matrix metals.
The results are as follows:
(1) Transition points T_A and T_B were observed in the thermal expansion curves for all the specimens measured. T_A corresponds to the transition from elastic to plastic deformation of the matrix, and T_B corresponds to the transition from plastic deformation to plastic flow of the matrix.
(2) The linear thermal expansion coefficients of the composites measured in the longitudinal and transverse directions agreed very well with the values calculated from Schapery’s theoretical equations. In the calculation, the tensile moduli and Poisson’s ratios of the matrix alloys were used as the elastic values below T_A temperature, while E_m=0 GPa and ν_m=0.5 were used as plastic values for temperatures above T_B.
(3) From the above values, the linear thermal expansion coefficients were calculated for arbitrary directions by modifying the Uemura’s theoretical equation. In the ranges of (T₀−T_A) and (T_B−T₅₇₃), a good correlation was obtained between the calculated and observed coefficients.