Study On Conformal Fixture For Heat-Treatment Of Thin Curved Ti-Alloy Boom

The conformal fixture is one of the key technologies of the heat-treatment deformation control on thin curved Ti-alloy boom. In this paper, numerical simulation, theoretical analysis and experiments were combined, from the aspects of heat-treatment process parameters, fixture structure and clamping fixture layout, to control the heat-treatment deformation of thin curved Ti-alloy boom. The main content in this paper can be summarized as follows:(1) Based on the coefficient of thermal expansion, high temperature performance, economic, et al, the materials of heat-treatment fixture were screened. With the theoretical analysis of the free, half bound and fully constrained, the reasonable tooling fixture material was determined.(2) In order to find out the effects of different factors to the results of hot sizing, the modularized tooling was designed and the hot sizing experiments were carried out. The effects of annealing treating parameters, such as temperature, heating rate, holding time and the cooling rate, were investigated in the experiments. With the combination of Ti-alloy mechanical properties, The optimization scheme of heat-treatment process parameters was determined at last.(3) Two different loading modes were designed and the finite element analysis was constructed to optimize the load distribution and clamping fixture layout, which was analyzed compared to the experiments of T-shape thin-wall parts.(4) The annealing experiment of partial thin curved Ti-alloy boom was carried out and the results proved that the optimization schemes of heat-treatment process parameters and the clamping fixture layout would decrease the heat-treatment deformation.