2021 Volume 93 Issue 7 Pages 404-407
Non-heat treated Al-Mg based alloy is expected to be applicable as automotive body parts material due to its ductility. In this study, lower link arms, an automotive rear suspension part, were produced by high pressure die casting using Al-4.5Mg-1.0Mn based alloy. The influence of both the amount of die lubricant and added amount of Ti, B, and Sr on the hot crack length of the lower link arm was investigated. It was found that, as a result of changing the amount of the die lubricant, the crack length became longer when the die lubricant coated was above a certain amount. As a result of adding variable amounts of Ti, B, and Sr under the same die lubricant coating conditions, the following two points were suggested. First, the addition of Ti, B, and Sr reduced the crack length at the side of the lower link when the mold temperature was controlled to above 190℃. On the other hand, the addition of Ti, B, and Sr did not reduce the crack length at the bottom of the lower link. This might be caused by the difference in the crack mode at these measurement points.
