Microstructure and mechanical properties of strontium-modified ADC12 alloy processed by heat treatment

作者：Huang Zhi-xiang; Yan Hong^*; Wang Zhi-wei

来源：Journal of Central South University (English Edition), 2018, 25(6): 1263-1273.

DOI：10.1007/s11771-018-3823-7

• ADC12 alloy
• strontium
• heat treatment
• microstructure
• mechanical properties

The effects of heat treatment and strontium (Sr) addition on the microstructure and mechanical properties of ADC12 alloys were investigated, and two-stage solution treatment was introduced. The results indicated that the addition of Sr obviously refined the microstructure of ADC12 alloys. When 0.05 wt% Sr was added into the alloy, the eutectic Si phase was fully modified into fine fibrous structure; alpha-Al and beta-Al5FeSi phases were best refined; and the eutectic Al2Cu phase was modified into block-like Al2Cu phase that continuously distributed at the grain boundary. The ultimate tensile strength (UTS) (270.63 MPa) and elongation (3.19%) were increased by 51.2% and 73.4% respectively compared with unmodified alloys. After the two-stage solution treatment (500 A degrees C, 6 h+520 A degrees C, 4 h), for 0.05 wt% Sr modified ADC12 alloys, the Si phases transformed into fine particle structure and Al2Cu phases were fully dissolved. The peak hardness value of the alloys processed by the two-stage solution treatment was increased by 8.3% and 6.8% respectively compared to solution treatment at 500 A degrees C and 520 A degrees C. After the aging treatment (175 A degrees C, 7 h), the hardness and UTS were increased by 38.73% and 13.96% respectively when compared with the unmodified alloy.

• 出版日期2018-6
• 单位南昌大学