金属材料超塑性一般要求具有均匀细小的等轴晶粒,并且在高温超塑变形过程中能够保持晶粒尺寸稳定性,避免晶粒快速长大。轻合金的超塑性不仅要具备等轴细晶组织,还需要通过引入第二相或合金元素等来保证材料的高温组织稳定性,这也是当前金属材料超塑性的研究热点之一。目前提高超塑性材料细晶组织稳定性的策略主要包括：析出第二相粒子钉扎晶界,双相合金的相结构之间抑制彼此生长,复合材料的增强体抑制晶粒长大以及单相合金的溶质原子偏聚等。本文概述了含析出第二相合金、双相合金、金属基复合材料和单相合金等轻合金超塑性组织稳定性的研究现状,并从工业应用需求及降低生产成本的角度,提出了超塑性材料的发展趋势。

There have been numerous attempts to achieve superplasticity in light alloy materials for improving the formability and manufacture efficiency of them. However, the superplasticity of light alloy is difficult to realize for the uniform fine equiaxed grains, which are generally required by superplasticity, tend to rapidly grow during high temperature deformation. That means the superplasticity of light alloys not only requires an equiaxed fine-grained structure, but also needs to ensure the high-temperature structural stability. Thus, adding a second phase or alloying elements become one of the current research hotspots on superplasticity of light alloy materials. Currently, the main strategies for improving stability of the fine-grained structure of superplastic light alloy materials can be summarized as: introduction of second-phase particles pinning grain boundaries, phase structure of dual-phase alloys to inhibit growth between each other and reinforcement of composite materials inhibiting grain growth as well as utilizing solute segregation of single-phase alloys. This paper summarizes the research status of superplastic microstructure stability of light alloys including second-phase-containing alloys, duplex alloys, metal matrix composites and single-phase alloys. Finally, the paper proposes the development trend of superplastic light alloy materials from the perspective of industrial applications and cost-reduction requirements. Increasing the variety of alloying element, decreasing the content of alloying element, simplifying the process of manufacture and achieving low temperature superplasticity and high strain-rate superplasticity will be the development trend of superplastic light alloy materials.