The effect of loading on the rupture structure of Al–Si alloys at elevated temperature

Two Al–Si alloys of different silicon content having 10 and 15 wt.% were tested by loading at an isothermal temperature of 540 °C. To explore the characteristics of the rupture structure, various loads (2–80 N) were chosen in this study. The results indicate that the rupture structures are mainly affected by transformation stress under lower load. Besides, the dissolved silicon is trended to distribute along α-Al dendrite boundary, but it is gradually governed by the increased loading-effect and restrain the distribution of eutectic silicon. Based on the both interactions, the two changing curves of rupture time reveal commonly a trend of that initial decrease and then increase, whereas the TR-value of 15 Si is larger than 10 Si. To increase the load will raise generally the hardness of rupture. However, this hardness of 10 Si is higher under 15 N-loaded below. The cracking paths were more preferred to proceed along the silicon particles clustered zone.