Effects of Heat Treatment and Amount of SiC Particles on Fatigue and Fretting Fatigue Strengths of Particulate Reinforced A2024 Alloy Composite

A study has been made of the effects of mechanical properties of the matrix and the amount of SiC particles on fatigue strength and fretting fatigue strength using 2024-T6 heat treated (T6) and 2024-O heat treated (O) Al alloy metal matrix composites reinforced with 10, 20 and 25 vol%SiC particles with the mean size of 2 μm. The 107 cycles plain fatigue and fretting fatigue strengths of the T6-composites increased but then decreased with an increase in the amount of SiC, having a maximum value at about 20%, while those of the O-composites increased with an increase in the amount of SiC up to 25%. The 107 cycles plain fatigue strengths of the T6- and O-composites were nearly equal to those estimated on the basis of the change of the elastic modulus and the ultimate tensile strength due to the reinforcement. The 107 cycles fretting fatigue strengths of the T6- and O-composites were higher and lower, respectively, than the estimated ones.