Cause Analysis of Surface Bubbles of Spray-formed 7055 Aluminum Samples

Bubbles appeared on the surface of tensile samples made of spray-formed 7055 aluminum during solution heat treatment. Marco and micro inspection was carried out on the surface and sections of the samples, and also on the fracture surface after tensile test. Furthermore, tensile testing, hydrogen content testing and metallurgical structure analysis were also carried out on the samples with bubbles. The results show that the surface bubbles of the samples formed due to high temperature oxidation by higher humidity in the heat treatment furnace. It is suggested that surface machining should be used to remove the bubbles of the samples.