Study On Explosive Welding Of Rare Metals And Heat Treatment Method

Rare metals such as titanium, zirconium and tantalum are promising materials in petrochemistry and chemical industry due to the outstanding properties such as high strength and anti-causticity. These materials can be used to manufacture special equipments such as pressure vessel. Steel plate is often used to fabricate layered materials with rare metal plate because of the high price of rare metels. Explosive welding is a practical and reliable technology to manufacture composite plates of rare metals and steel plates.Application of the composite plates of rare metals and steel plates is beneficial for the aeronautic, petrochemistry, electrical and chemical industries and ocean engineering etc. The study of explosive welding parameters, thermodynamic and materials performance on the interface as well as the heat treatment technics will benefit to the study of explosive welding technology and accelerate the syncretion of explosive mechanics, metal physics and materials.Aiming at the explosive welding technology of rare metals and steel plates, the2to3layer explosive welding window and parameters, heat treatment technics of rare metal composite plates, influence factors of combination strength on the interface as well as the influence factors and the control methods of big area and high combination ratio are all studied in this thesis, the main research products of this paper are as follows:1) Calculation of2to3layer explosive welding windows and parameters:A calculation method was established to calculate2to3layer explosive welding windows and parameters. Calculation program V3.0was compiled to protract the explosive welding windows and calculate the offset distance.2) Study on the explosive welding technology of the2layer titanium/steel and3layer3layer zirconium/titanium/steel:little obliquity experiments and simulation work by SPH meshless methods were adopted to study the variational parameters during explosive welding. Microcosmic photograph, shear strength and elements distribution on the interface were analyzed. The influence of impact velocity, impact angle and pressure on the wavy interface, shear strength and element diffusion were also discussed.3) Heat treatment technics of titanium/steel and zirconium/titanium/steel composite plates: different heat treatment technics were adopted for the titanium/steel and zirconium/titanium/steel composite plates. The microcosmic photograph, elements distribution and shear strength were analyzed and the influence of temperature on the composite materials properties was also discussed. 4) Influence factors on combination strength and the control methods:influence factors such as whirlpool, elements diffusion, adiabatic shear band and air vent which are often found near the interface were analyzed. Physical parameters distribution especially the strain, tempetature distribution were calculated by SPH method. The formation mechanism and control method of the influence factors mentioned above were discussed according to the experimental and numerical results.5) Influence factors on big area and high combination ratio and the control methods: formation process of boundary effects and ignition area effects which will affect the area and combination ratio were analyzed. The calculation method was proposed to analyze the influence quantificationally. The control methods and technical measures were put forward to avoid the boundary effects and ignition area effects.