Nanotechnology enabled casting of aluminum alloy 7075 turbines

Abstract

Aluminum alloy 7075 is well-known for its high-performance structural systems due to its lightweight and excellent mechanical properties. However, its susceptibility to hot cracking and limited fluidity hinder its casting suitability, posing challenges in manufacturing near-net-shaped structures economically, especially for thin and intricate aerospace components. This paper presents experimental results based on nano-treating, an emerging nanotechnology-enabled manufacturing method by incorporating a low fraction of nanoparticles in liquid aluminum, to allow the casting of complex aluminum alloy 7075 parts. Vacuum fluidity tests demonstrated that nano-treating of aluminum alloy 7075 with only 0.5 vol% TiC nanoparticles increased the fluidity of aluminum alloy 7075 by more than 20%, effectively eliminating hot cracking and enhancing surface quality. Through the Rapid Investment Casting process, nano-treated aluminum alloy 7075 can be successfully cast into turbines with 0.5 mm thick blades. In contrast, aluminum alloy 7075 without nano-treating failed to produce good casting quality due to poor filling and severe cracks. The manufacturing trials highlight the significant improvement in castability achieved through nano-treating, opening a novel pathway for the cost-effective production of complex aluminum alloy 7075 structures for numerous applications.