Mechanical Properties of an RSP / PM Al - Fe - V - Si Alloy (1) ( Microstructure and mechanical properties )
이종철Jong Cheol Lee, 이성학Sung Hak Lee, 이두영Doo Young Lee, 김낙준Nack Joon Kim
Abstract
This paper identified the main metallurgical factor leading to the embrittlement of an RSP/PM AI-Fe-V-Si alloy after high temperature exposure above 480℃. Although the RSP/PM AI-Fe-V-Si alloy shows excellent high temperature stability compared with an IM 2219 Al alloy, the RSP/PM alloy exhibits the very uncommon behavior that the ductility and fracture toughness of the alloy decrease along with the yield strength after high temperature exposure. Detailed microstructural analyses suggest that the formation of coarse θ-Al₃Fe phase in the form of band structure causes the embrittlement of the alloy exposed to temperatures above 480℃. Also, it is found that the non-uniform distribution of the silicide dispersoids due to the cooling rate difference between the wheel side and the air side of melt spun ribbons is responsible for the formation of θ-Al₃Fe phases. Therfore, it is concluded that the achievement of the uniform microstructure by the control of RSP condition is essential for the safe application of RSP/PM Al alloys at higher temperatures.