ZL116 aluminum alloy has excellent casting performance, low hot cracking tendency, high air tightness, good mechanical properties, corrosion resistance and welding performance. It is mainly used to manufacture complex castings bearing medium load, such as aircraft engine shell, pump body, aircraft large structural parts, etc.
The influence of the change of elements in the alloy on the properties of ZL116 aluminum alloy has always been one of the hot spots of researchers. Yanglijuan et al. Carried out the research on the effect of Mg content change on the microstructure and properties of counter gravity casting ZL116 alloy, and found that the ZL116 alloy with the same Mg content, and the alloy with differential pressure casting in counter gravity casting, had the best mechanical properties. With the increase of Mg content, the tensile strength of ZL116 alloy increased. He Yike et al. Studied the effect of Nd element on the microstructure and properties of counter gravity casting ZL116 alloy, and found that nd element can modify the eutectic phase in ZL116 alloy, promote the spheroidization of eutectic Si, and further improve the strength and plasticity of the alloy. For cast aluminum alloy, the casting method is very important to its properties. Many scholars have carried out research on the effects of different casting methods on its microstructure and properties. Zhao Dazhi et al. Studied the influence of casting speed on the microstructure of the alloy by near liquidus semi continuous casting, and found the best casting speed range to obtain uniform and fine ingot microstructure. Taking ZL116 alloy as an example, luguimin et al. Introduced the research progress of aluminum alloy semi-solid forming, and put forward new ideas and methods for semi-solid alloy design. The core purpose is to obtain uniform and fine rose like distribution structure by reasonable process, so as to improve the comprehensive properties of the alloy. The general process flow of cast aluminum alloy components is as follows:
Casting – physical and chemical inspection – flaw detection – machining – anodizing. Some scholars pay attention to the influence of machining and anodizing on the properties of ZL116 alloy castings. Xueying designed and developed a sealing process for aluminum alloy anodizing to further improve the corrosion resistance of aluminum alloy anodizing film. Zhangyejun et al. Studied the machining process of aluminum alloy casting shell with complex shape, and solved the machining problem between the plane and the inner hole by accurately selecting the rough machining and finishing datum and reasonably allocating the machining allowance. In recent years, researchers have paid more and more attention to the failure causes of aluminum alloy castings, because they are directly related to the reliability and safety of castings in service. Chentilei et al. Studied the causes of cracking of ZL116 bearing during repair welding and found that the rapid growth of fatigue crack caused by welding defects is the direct cause of bearing cracking.
By observing the fracture of the support arm of ZL116 alloy casting, the preparation process was analyzed, and the cracking reason of the support arm was explored. By studying the structure and properties of the broken arm and observing the fracture of the arm, it is found that the fracture of the arm is caused by the cracks in the transition area of the arm bend during the machining of the casting blank. According to this, the production process of the arm component is improved and the hidden trouble is eliminated.