The influence of Cu content on the microstructure and hardness of near-eutectic Al-Si-xCu（x = 2%,3%,4% and 5%） was investigated.After melting Al-based alloys with different Cu contents,alloys were cast in green sand...The influence of Cu content on the microstructure and hardness of near-eutectic Al-Si-xCu（x = 2%,3%,4% and 5%） was investigated.After melting Al-based alloys with different Cu contents,alloys were cast in green sand molds at 690 °C and solidified.The solution treatment was performed at 500 °C for 7 h and then the specimens were cooled by water quenching.The samples were respectively aged at 190 °C for 5,10 and 15 h to observe the effect of aging time on the hardness of matrix.Also differential thermal analysis was used to obtain the transition temperature of the equilibrium phases at cooling rate of 30 K/min and to determine the effect of Cu content on the formation of quaternary eutectic phases and the melting point of-（Al） ＋ Si.The results show that as Cu content in the alloy increases,the hardness of matrix increases due to precipitation hardening,the melting point of -（Al） ＋ Si decreases and the amount of these eutectic phases increases,quaternary eutectic phase with melting point of 507 -C forms when Cu content is more than 2%.展开更多
Al4Cu2Ni2Mg alloy is an age-hardenable aluminum alloy. The effect of different solution and aging heat treatment conditions on the microstructure, hardness and wear resistance of the alloy was studied. The cast specim...Al4Cu2Ni2Mg alloy is an age-hardenable aluminum alloy. The effect of different solution and aging heat treatment conditions on the microstructure, hardness and wear resistance of the alloy was studied. The cast specimens were solution treated and then artificially aged. Optical microscopy and scanning electron microscopy were used to investigate the microstructures of the specimens. The hardness and wear tests were applied to understanding the effects of heat treatment. After aging for 8 h, the hardness of the alloy increases from HV 10 96.5 to 151.1. Aging treatment for a longer duration causes a drop in the hardness because of over aging. Increasing the hardness of the alloy increases the wear resistance. As a result of all tests, solution heat treatment at 540 °C for 8 h and aging at 190 °C for 8 h were chosen for optimum heat treatment conditions for this alloy.展开更多
基金Project (2003K/20790) supported by the State Planning Organization,TurkeyProject (2009/038) supported by the Scientific Research Projects at Kocaeli University,Turkey
文摘The influence of Cu content on the microstructure and hardness of near-eutectic Al-Si-xCu（x = 2%,3%,4% and 5%） was investigated.After melting Al-based alloys with different Cu contents,alloys were cast in green sand molds at 690 °C and solidified.The solution treatment was performed at 500 °C for 7 h and then the specimens were cooled by water quenching.The samples were respectively aged at 190 °C for 5,10 and 15 h to observe the effect of aging time on the hardness of matrix.Also differential thermal analysis was used to obtain the transition temperature of the equilibrium phases at cooling rate of 30 K/min and to determine the effect of Cu content on the formation of quaternary eutectic phases and the melting point of-（Al） ＋ Si.The results show that as Cu content in the alloy increases,the hardness of matrix increases due to precipitation hardening,the melting point of -（Al） ＋ Si decreases and the amount of these eutectic phases increases,quaternary eutectic phase with melting point of 507 -C forms when Cu content is more than 2%.
文摘Al4Cu2Ni2Mg alloy is an age-hardenable aluminum alloy. The effect of different solution and aging heat treatment conditions on the microstructure, hardness and wear resistance of the alloy was studied. The cast specimens were solution treated and then artificially aged. Optical microscopy and scanning electron microscopy were used to investigate the microstructures of the specimens. The hardness and wear tests were applied to understanding the effects of heat treatment. After aging for 8 h, the hardness of the alloy increases from HV 10 96.5 to 151.1. Aging treatment for a longer duration causes a drop in the hardness because of over aging. Increasing the hardness of the alloy increases the wear resistance. As a result of all tests, solution heat treatment at 540 °C for 8 h and aging at 190 °C for 8 h were chosen for optimum heat treatment conditions for this alloy.
