Open AccessThermophysical properties and rapid solidification of Al-Cu-Ge alloys
Author(s) -
王小娟,
阮莹,
洪振宇
Publication year - 2014
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.63.098101
Subject(s) - eutectic system , materials science , alloy , thermodynamics , nucleation , ternary operation , microstructure , thermal expansion , atmospheric temperature range , metallurgy , physics , computer science , programming language
Al-Cu-Ge alloy system, a typical ternary eutectic alloy system, has been used widely in the industries. Our research is helpful for better understanding its thermophysical properties and improving its structural performance. In this paper, the specific heat values and thermal expansion coefficients of Al55Cu10Ge35, Al70Cu10Ge20 and Al80Cu10Ge10 alloys are investigated. The microstructural characteristics and the solidification paths of these alloys under near-equilibrium solidification and rapid solidification conditions are studied comparatively. Their specific heat values increase as Al content increases and Ge content decreases. The softening temperature is 666 K, and the thermal expansion coefficient fluctuates around 1.5×10-5 K-1 in the temperature range of 370–650 K. Under a near-equilibrium solidification condition, the last formation microstructure is (Al)+(Ge) pseudobinary eutectic instead of ternary eutectic. This means that (Al), (Ge), and CuAl2 phases are difficult to nucleate simultaneously or grow cooperatively. In comparison, during rapid solidification, the nucleation of primary phase is depressed, pseudobinary eutectic and ternary eutectic are much easier to form in these alloys.