Study On The Key Technology Of Connection Of AZ80 Magnesium Alloy Parent Material And Steel Ring

With the extensive application of the magnesium alloy, the question that connected the magnesium alloy with hetero metal is displayed in many fields, especially in aviation, spaceflight, traffic, war industry and so on. The connection of the magnesium alloy and hetero metal can bring into play each material's inhere characteristic. So the study of the connection of the magnesium alloy and hetero metal take on grave application values.In this article, taking AZ80 magnesium alloy parent material and 38CrSi as object of study, the author researches their hot assembly's questions. In the process of extrusion, the parent material exists the higher resistance to deformation, metal flow asymmetry, join with wear steel ring insufficiently, and the different heat expansion coefficient of the cast condition AZ80 magnesium alloy and the steel ring, the cooling shrinkage not consistently in the hot assembly process. By carrying on the deforming processing through the extrusion to the AZ80 magnesium alloy can refine alloy organization, improve the thermal-expansion coefficient of the magnesium alloy, and simultaneously realize the connection between the loading wheel and the metal ring through the extrusion craft.The experiment shows that the thermal-expansion coefficient of the magnesium alloy is nonlinear variation in 100℃~ 450℃, and besides AZ80-EX-410℃, others heighten slowly along with the temperature heighten first, the temperature achieves 200℃when the thermal-expansion coefficient obviously elevates and between in 300℃~350℃achieve the peak value, then reduce tends to be stable rapidly. Because AZ80 magnesium alloy after extrusion has had the dynamic recrystallization as well as the plastic deformation fine crystal invigoration effect, not only the linear expansion coefficient is obviously lower than the cast condition, but also the fluctuation range of the expansion coefficient along with the temperature rising is obviously lower than the cast condition.Considering the cooling shrinkage uniformity of the AZ80 magnesium alloy and 38CrSi steel ring in the hot assembly process, this article chooses AZ80 finally in 380℃and 38CrSi in 450℃carry on the big forming, and realizes the two's connection. After finishing the forming, the parent material is heated up to 250℃again, and kepted warm 3h. Then inverse it and carry on the reshaping forming, guarantee the two's close connection.