Temperature effect analysis of additives in self-propagating forming aluminum alloy cylinder inner wall coating
The high temperature of self-propagation is about 1000℃,which exceeds the tolerable temperature of 502～638℃ of the bearing temperature of aluminum alloy tube and causes thermal damage to the aluminum alloy substrate,while Si,Ti and Mo,as the additive phases,can reduce the temperature of self-propagation aluminum thermal reaction by activating the crystal lattice and wetting the interface.In this paper,low-temperature self-propagation technology is used to prepare wear-resistant coatings on the inner wall of aluminum alloy tubes with small inner diameters,and investigated the effect of added phases(Si,Ti,and Mo)on reducing the temperature of the self-propagating aluminothermal reaction system.Orthogonal experiments were used to determine process parameters such as the optimal ratio of aluminothermic agents,additive phases,and cooling pressure,and the cooling mechanism of additive phases was studied.The results show that the traditional aluminothermic reaction process releases a large amount of heat.Adding Si and Ti phases can lower the reaction temperature,slow down the severity of the reaction,and even inhibit the progress of the reaction.Adding an appropriate amount of Mo will cause the aluminothermic reaction to occur again.The Exothermic reaction temperature of the self-propagating reaction system with all added phases is about l00℃ lower than that of the aluminothermic reaction,and the weight loss at high temperature is at least 1.33％.The optimal ratio is:the cooling gas pressure is 0.2 MPa,the mass fraction of the added phase is 6％,and the mass fraction of thermite is 94％.
万方数据
维普
