Fig reports the evolution of the applied and

1. Introduction
The air-cooled heat exchangers or radiators of automobiles have a significant role in engine efficiency and weight. The aluminum radiators are widely used in passenger cars because of their good thermal conductivity, lightweight, and brazing ability. However, the brazing joint of aluminum alloy loses its strength when the service temperature is higher than 150 °C. At present, the higher service temperature of the engine is driven by the requirements of high power output as well as low SNX-5422 consumption of engine. Accordingly, the copper alloys become the good alternative alloys for automobile radiators due to their high thermal conductivity, high strength, and high service temperature.
Fig. 1. Failure of Al-alloy brazing joints of an engine radiator after 1.5 × 104 cycles of cyclic torsion.Figure optionsDownload full-size imageDownload as PowerPoint slide
During service, the engine radiator is subjected to various types of loading, i.e. tension, compression and torsion. Unfortunately, none of the research works have been evaluated the torsional strength and torsional failure of brazing joint of Cu alloys. Therefore, it is the objective of this work to investigate the torsional strength and failure of the Cu-alloy brazing joint. The contributions of joint thickness, joint defect and joint microstructure to the torsional strength of brazing joint were investigated, and then the mechanism of torsional failure was discussed.