Application of High-Frequency Induction Heating Apparatus to Heat Treatment of 6061 Aluminum Alloy

Abstract

A high-frequency induction heating apparatus was used for the heat treatment of a commercial 6061 aluminum alloy bar with the objective of improving the mechanical properties and productivity. Heating states of the 6061 alloy bar were examined in terms of temperature distribution, heating rate, overheating and temperature fluctuation; moreover, the mechanical properties of the alloy after heat treatment were also investigated. The results of this study are as follows. When the 6061 alloy bar was rapidly heated to the heat treatment temperature using the induction heating apparatus, temperature distribution and overheating of the sample were small as well as the temperature fluctuations in the holding process. A rapid heating rate of about 21°C/s heated the sample to the heat treatment temperature of 560°C in 26 s. The sample showed equivalent or superior mechanical properties compared with a sample heated by conventional electric furnace. Temperature and time of the heat treatment process greatly influenced the mechanical properties of the 6061 alloy, while there was no significant difference in mechanical properties of the sample heat-treated at various heating rates.