A novel heat-resistant Al-Si-Cu-Ni-Mg base material synergistically strengthened by Ni-rich intermetallics and nano-AlNp microskeletons

作者：Hu, Kaiqi; Xu, Qingfei; Ma, Xia; Sun, Qianqian; Gao, Tong; Liu, Xiangfa^*

来源：Journal of Materials Science & Technology, 2019, 35(3): 306-312.

DOI：10.1016/j.jmst.2018.09.051

• Al-Si alloy
• Heat-resistant Al alloy
• Mechanical properties at high temperatures
• Nano-AIN(p) microskeletons

In this work, nano-AlN particle (nano-AlNp) microskeletons were introduced into an Al-Si-Cu-Ni-Mg alloy by Al-8AlN master alloy in which the nano-AlNp reinforcements connect with each other to form three-dimensional networks. It is found that these nano-AlNp microskeletons mainly distribute in the binary Al-Si eutectic zones resulting in flaky eutectic Si phases being modified to particulates. Meanwhile, the microskeletons strengthen the matrix synergistically with semi-continuous Ni-rich intermetallics in three dimensions. The tensile mechanical properties, micro-hardness and thermal expansion properties of the alloy at different temperatures are significantly improved. Especially, the ultimate tensile strength (UTS) at 350 degrees C increases from 85 MPa to 106 MPa, rising by 24.7%, which is ascribed to nano-AlNp microskeletons assisting intermetallics with undertaking mechanical loading, and to the modification of eutectic Si phases to reduce the stress concentration at elevated temperatures.

• 出版日期2019-3
• 单位山东大学