Correction to Braunovic & Alexandrov’s 1994 article on intermetallic compounds at aluminum-to-copper electrical interfaces

Interest in aluminium and copper joining processes has increased in recent years due to the growing appeal of using aluminium in electrical applications. Braunovic & Alexandrov’s 1994 article, Intermetallic Compounds at Aluminum-to-Copper Electrical Interfaces: Effect of Temperature and Electric Current, has become a seminal contribution on Al-Cu joining for electrical applications. Their detailed measurements of resistance and intermetallic diffusion rates have become a baseline for assessing the operational performance of Al-Cu joints. The paper has had an increasing citation rate since publication and is in multiple electrical contacts textbooks. However, a minor error has been discovered in the presented analysis. In this short communication, the error is identified and a corrected analysis is provided. The corrected analysis shows that Al-Cu intermetallic growth is ten times slower than previously presented. The corrected analysis has a consequential impact on the utility of Al-Cu joints in electrical applications. Therefore, highlighting the error provides valuable insight for utilising and developing Al-Cu welding in electrical applications.