| 초음파 용탕 처리가 Al-7Si-0.35Mg 알루미늄 합금의 미세조직 및 기계적 특성에 미치는 영향 |
| 김수배1,2, 조영희1, 이정무1, 정재길1, 임수근2 |
1재료연구소(KIMS) 실용화연구단
2경상대학교 나노신소재공학부 |
| The Effect of Ultrasonic Melt Treatment on the Microstructure and Mechanical Properties of Al-7Si-0.35Mg Casting Alloys |
| Soo-Bae Kim1,2, Young-Hee Cho1, Jung-Moo Lee1, Jae-Gil Jung1, Su Gun Lim2 |
1Implementation Research Division, Korea Institute of Materials Science, Changwon 51508, Republic of Korea
2School of Materials Science and Engineering, Gyeongsang National University, Jinju 52828, Republic of Korea |
|
|
|
Received: 4 May 2016; Accepted: 5 October 2016. Published online: 6 April 2017. |
|
|
| |
| ABSTRACT |
|
The effect of ultrasonic melt treatment (UST) on the microstructure and mechanical properties of Al-7Si-0.35Mg (A356) casting alloys was investigated. The particular aim of this study was to analyze the mechanism involved in the strengthening of the A356 alloys when fabricated by UST. The UST had little effect on the sizes of the α-Al grain and eutectic Si at a melt temperature of 750 ℃, and the yield strength of the A356 alloy was increased by UST by approximately 16%. After T6 heat treatment, however, both alloys prepared with and without UST had similar levels of yield strength. These results are possibly associated with a change in the type and the volume fraction of intermetallics due to UST. UST greatly reduced the volume fractions of the intermetallics which were formed upon solidification, resulting in alloys with predominantly β-Al5FeSi instead of π-Al8FeMg3Si6. However, T6 heat treatment, especially a solid solution treatment at 530 ℃ for 8 hours, led to the dissolving of intermetallics such as Mg2Si and π -Al8FeMg3Si6 and as a result their volume fractions were further reduced to similar levels in both alloys with and without UST. |
| Keywords:
hypoeutectic Al-Si alloy, casting, ultrasonic melt treatment, microstructure, mechanical properties |
|
PDF Links
Full text via DOI
Download Citation 
Print 
