High Quality Magnesium Alloy Pipe Preparation AndApplied Basic Research

In aviation,aerospace, transportation, military equipment and so on, the pipe asthe important structural materials has been more and more widely used, at the sametime proposes some new requirements such as lightweight, recyclable, resistance toelectromagnetic interference. AZ31B magnesium alloy has many unique advantages,but low plasticity at room temperature limitS the application of AZ31B magnesiumalloy, which makes its potential is far from complete. The plastic forming technologyof magnesium alloys is still in the experimental research stage, while the AZ31Bmagnesium alloy tube directly pushing bending process is an important direction ofthe magnesium alloy research.In this paper, invents the tube billet heating device, with existing push bendingmachine in the enterprise is as forming equipment, by the orthogonal experiment thethe reasonable technological parameters is to determine and adopts of deformationobtained reasonable small deformation of high quality magnesium alloy tube formingperformance optimization scheme. Guided by the optimization of process, AZ31Bmagnesium alloy tube billet directly push bending plastic forming. Throughmetallographic observation, X-ray diffraction analysis, mechanical property analysisand scanning electron microscopy (sem) analysis method, The microstructureevolution, tensile deformation behavior and fracture mechanism of extrusion AZ31Bmagnesium alloy was studied systematically under different processing parameters ofpipe after forming. Analyzed the status before and after the deformationmicrostructure, mechanical properties and the forming quality of the samples and thepush system temperature, push speed and lubrication condition. Experiments showthat push the system temperature has a very limited on the formability of pipe fittings,with push system, pushing speed of the rise of temperature decreasing and theimprovement of the performance of the lubrication, the push pipe fittings made of finegrain, the more, the better comprehensive mechanical properties, the quality of thepipe is higher. Under the system of low temperature and low speed organization grainis relatively bulky, scattered distribution with small grain size, the organization is notuniform, the pipe tensile strength is not high, and elongation is low. With theimprovement of system temperature and lubrication performance, to the hightemperature of300℃, the original billet in the coarse grain in the outside world under the function of stress and the mandrel, broken, the stress under the action of new grainformation, and the relative rotation of the intergranular makes deformationorganization recrystallization happens, small grain size. After the forming oforganization for the fine equiaxed grain, and uniform distribution, pipe fittings oftensile strength reached303mpa, while the elongation reached17.8%, effectivelyincrease the mechanical properties ofAZ31B magnesium alloy.In short, in this paper, by investigating the push of AZ31B magnesium alloy tubebending extrusion process, push the system temperature and pushing velocity andlubrication condition on the microstructure and mechanical properties and the effectof grain refinement of magnesium alloy and performance change regularity andmechanism, for small diameter high performance magnesium alloy tube directly pushbending process to provide the basis.