HIPによるアルミ合金鋳物の疲労強度の改善

概要

論文の詳細を見る
The influence of HIP treatment on the fatigue reliability of aluminum alloy castings was investigated. The main results obtained were as follows : (1) The fatigue strength of HIP-treated castings was improved by 20% 〜 30% by the HIP treatment. (2) As the cooling rate of HIP-treated castings was increased, the microstructure was controlled fine. The fatigue strength of HIP-treated castings produced using a rapid cooling rate was greater than that produced using a slow coolling rate. (3) According to the S/δ_0.2 N diagram, it could be understood that the fatigue strength of HIP-treated castings was mutually related to the yield strength. (4) The effect of stress gradient on 10^7 fatigue strength of HIP-treated castings was less than that on non-HIP-treated castings. (5) The plane facet induced by slip was always observed at the origin of the fatigue crack in HIP-treated castings. Hence it could be concluded that the fatigue strength of HIP-treated castings was improved because the porosities were reduced by HIP treatment. (6) From SEM fractographs, it is considered that the fatigue life is controlled by the plane facet size at the origin of the fatigue crack, that is, the primary crystal size of aluminum.
社団法人日本機械学会の論文
1995-06-25