Influence of Humidity on a Shot Peened Aluminium Alloy Piece

Author:  Daisuke Gowa, Yuji Kobayashi, Takanori Nagano
Source:  ICSP-13
Doc ID:  2017053
Year of Publication:  2017
Abstract:  
Introduction: Aluminium alloy 7075 is an aluminium alloy, with zinc as the primary alloying element. It is strong,with a strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Aluminium alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable. The first 7075 was developed in secret by a Japanese company, Sumitomo Metal, in 1943. 7075 was eventually used for airframe production in the Imperial Japanese Navy. 7000 series alloys such as 7075 are often used in transport applications, including marine, automotive and aviation, due to their high strength-to-density ratio. Their strength and light weight are also desirable in other fields. Rock climbing equipment, bicycle components, inline skating-frames and hang glider airframes are commonly made from 7075 aluminium alloy. Generally many airplane components are made of Aluminium alloy. As this alloy has good fatigue strength but low resistance to corrosion, it is necessary to maintain low-humidity air inside the airplane. Because of this, the airplane’s conditioned air works in low temperatures, in order to provide dry air. In this study, the specimens were applied to a rotating bending fatigue strength test under two conditions: dry air (humidity = 25%) and moist air (humidity = 85%). The specimens manufactured in aluminium alloy 7075 material were shot peened.