Manufacture And Interface Diffusion Of Al/A Z31/Al Layered Composite Plate

In many practical applications, the low temperature poor corrosion resistance of magnesium alloys is one of the main disadvantages of magnesium alloy product development and application. If covered with aluminum on magnesium alloy, composite by rolling, thereby improving the corrosion resistance of magnesium alloys can be used in this experiment to try.Al / AZ31 / Al composite sheet by hot rolling complex approach. Studied the rolling temperature, pressure ratio on the bonding strength of the composite plate, and the impact on bond strength and interface structure of the composite plate annealing process after rolling; interfacial bonding mechanism to explore the use of diffusion kinetics theory, to determine the optimum program.The results show that :1. Best rolling complex process parameters: heating temperature control at 400℃, the reduction ratio of 35% to 50%. In this condition, a good surface quality of the composite plate, no significant wrinkles, a good combination of the composite plate, composite layer, no significant cracking and separation phenomena.2. Rolling appropriate composite diffusion annealing can further improve the bonding layer thickness of the composite panels, but if improper annealing process control, the interface will form a brittle compound led to a sharp decline in bond strength of composite board. So in actual industrial production, diffusion annealing treatment after rolling system developed must be strictly controlled. Diffusion annealing system is recommended for : annealing temperature 250℃, annealing time 60 min. Under this system annealing, rolling temperature 400℃, the bonding strength reduction rate of 40% of the composite panels is very good, no compound interface appears.3. With the growth of the annealing time and temperature increases the thickness of the compound layer also grows, compound growth over time, the relationship between the thickness of the parabolic law. Intermediate compound layer of the element composition analysis concluded that the aluminum layer is close to Mg2Al3, while close to one elemental magnesium composition close Mg17Al12.4. Use skill to learn interface diffusion method to calculate the thickness of the interfacial solid state reaction300-250℃℃?x =1.7×10-7×exp(-2938/RT) ×t1/2,(m)...