抄録
The effect of bolt materials on the bolt load loss behaviour of magnesium alloy AZ91D bolted joint at high temperature were clarified in this study. The bolt load loss tests were conducted under an initial bolt load of 4.5 kN for 100 h at ambient temperature and 100°C using magnesium alloy AZ91D plates assembled with steel SCM435 bolt and magnesium alloy AZ3 lbolt. From the results, magnesium alloy AZ91D bolted jointed clamped with steel bolt and AZ31 bolt showed the same performance of bolt load loss at the ambient temperature. For the tests at 100°C, magnesium alloys AZ91D bolted joint clamped with AZ31 bolt showed higher remained bolt load (66% of initial bolt load) after testing when compared with the one clamped with SCM435 bolt (42% of the initial bolt load). It was found the mismatch of thermal expansion between bolt and clamped part caused an additional tensile bolt load in SCM435 bolt which bolt load corresponded to increasing in an additional compressive stress on magnesium alloy AZ91D plates which played as an important role for driving creep deformation which could lead to the acceleration of bolt load relaxation.
