Bonding Strength and Grain Size Control of Dissimilar Joints of Al-Mg Alloys with Forge Welding

Autor: Shigeki Kakiuchi, Masaru Sato, Hideki Yamagishi
Rok vydání: 2020
Předmět:
Zdroj: Metallurgical and Materials Transactions A. 51:2154-2162
ISSN: 1543-1940
1073-5623
DOI: 10.1007/s11661-020-05682-8
Popis: High-productivity dissimilar bonding between A2024 aluminum (Al) alloy and AZ80 magnesium (Mg) alloy with a pure titanium (Ti) interlayer was achieved using forge welding with an alternating current (AC) servo press. This process involved diffusion bonding with plastic deformation in air. The tensile and fatigue strengths were compared between specimens prepared in the conventional way, which is considered the standard for bonding quality, and under the new rough condition. The tensile strengths were almost identical, but the fatigue strength with increasing number of cycles of specimens prepared under the rough condition was significantly lower than that of specimens prepared under the standard condition. Elemental analyses of cross-sections and the bonding interface revealed intermetallic compound (IMC) formation due to rupture of the Ti sheet. The difference in fatigue strength was attributed to a nonlinear effect on fatigue crack growth rate. Furthermore, in view of controlling grain size for practical use, the dynamic recrystallization behavior of the Mg alloy during this bonding process was investigated. The relationship between the grain size and Vickers hardness was in good agreement with the Hall–Petch relationship, and the Zener–Holloman parameter (Z parameter) explained the dynamic recrystallization process.
Databáze: OpenAIRE