Superplasticity of Magnesium Alloys
Magnesium alloys is a kind of promising material which has substantial weight and cost advantages over other conventional counterparts because of its unique mechanical properties, such as light-weight, good lubricity, excellent machinability and wear resistance. Superplasticity is a process which allows materials to deform greatly at normal medium temperature and achieve extraordinary formability in the hot processing forming. It is one of the most attractive new materials with rapid growth in recent years and has great potential in many applications. Magnesium alloys have significantly increased their popularity in many industries because of its ability to achieve superplasticity.
Superplasticity of magnesium alloys is defined as the ability to increase the strain rate of a fast-moving material, until it reaches its maximum elongation without fracture. In common forming processes, a certain percentage of ductility loss is observed after a certain number of deformation cycles, but the superplastic magnesium alloy can maintain its capability of further forming even after several strain cycles, a property which is much higher than other conventional types of materials.
This metallic structural material has two main advantages over other materials. First, it has a low-temperature superplasticity characteristic; the maximum strain rate without fracture can be as low as 0.2 micro-meter per second. Compared with temperature-activated deformation under certain stresses and constraints, the low-temperature superplastic deformation process can achieve higher strain rates than usual processes and can reduce the energy costs that are needed to realize the same forming process. Second, the special superplasticity of magnesium alloys can increases the formability and stretch ability dozens of times. Due to its ability to stretch and deform, it can take any complicated shape or form with fewer steps, which means huge savings in production time and costs.
The superplasticity of magnesium alloys is due to its inelastic micro-mechanics and the different phases of solidification in the molding process. During superplastic deformation, it is necessary to have appropriate plastic deformation, and the requirements of microstructural and mechanical property should be consistent with the forming processes in order to increase its superplasticity. The development of superplastic magnesium alloy has been greatly improved in recent years, as there has been a focus on improving their plasticity, mechanical properties, and structural stability.
The main application of superplasticity of magnesium alloy is in the aircraft industry, as its excellent performance can effectively reduce the weight of aircraft and therefore improve the overall performance of aircraft. The other important application is in the making of automobile components so that it contributes to narrowing the gap between fuel efficiency and better performance in vehicles. In addition, the use of magnesium alloy has also been widely used in medical equipment, as it is non-toxic, produces no secondary pollution, and does not cause any harm to the human body or environment.
In conclusion, due to the excellent performance of superplasticity of magnesium alloy, it has been widely used in the metal forming industry, such as automotive and aircraft industry, and its use is expected to increase in the near future. The superplasticity of magnesium alloy can effectively reduce pollution, reduce the production cost and time and improve the performance of vehicles and aircraft. With the rapid development of science and technology and the progress of production process, magnesium alloy is expected to be widely used in more areas in near future.
