Fatigue strength characteristics of aluminium alloy friction welded butt joints

• Published in: Welding international 1987-01, Vol.1 (7), p.649-654
• Main Authors: Ogawa, K, Ooue, Y, Nakayama, H, Morimoto, T, Hasui, A
• Format: Article
• Language: English
• ISSN: 0950-7116; 1754-2138
• DOI: 10.1080/09507118709453013

Previously abstracted from original as item 8805-4.5-0182A. Recently, friction welded butt joint has come into wider use for many mechanical structural elements, e.g. small scale crankshaft, etc. However, there exists some uneasiness in the practical use of this type of joint because of lack of strength data under service load or fatigue load conditions. It was planned to conduct a systematic study on fatigue behavior of this type of joint and a series of experiments has been carried out by using some joint specimens composed of similar metallic material. As a part of this study, rotating, bending fatigue tests were carried out to investigate the fatigue strength behavior of similar Al alloy friction-welded butt joint specimens. The results showed that the fatigue strength of the joint specimen produced under the welding condition of inertia type with high friction pressure was stronger than that of base material specimen. Furthermore, from detailed observations on the fatigue fractured surface, it was observed that the fractured surface of friction welded joint revealed uneven, flat plane with crack and dislocation, etc. in dimple pattern. It is concluded that the increasing trend in fatigue strength of similar Al alloy (5056) joint specimens depends on the metallurgical feature of the friction welded interface; in other words, that the disturbed layer existing at the interface gives a profitable effect on the fatigue strength of this type of joint. 11 ref.--X-ref.(UK/US).