高熵合金半固态坯机械合金化-热压致密-等温球晶化制备及触变成形机制

针对高熵合金变形抗力高、构件成形难的制造瓶颈问题，采用机械合金化实现固相合成高熵合金预合金粉末，借助真空热压烧结实现高熵合金块体材料的制备，在此基础上利用半固态等温处理方法实现高熵合金半固态坯料制备。从而提出机械合金化-热压致密-等温球晶化制备高熵合金半固态坯料新方法。将其利用至高熵合金半固态触变成形技术中，实现高质量高熵合金合金构件的近净成形制造。项目主要研究高熵合金预合金粉末机械合金化制备工艺参数及其组织性能调控机制、高熵合金块体材料热压烧结工艺优化及致密化机理、高熵合金半固态微观组织演变规律、高熵合金半固态流变学、高熵合金半固态触变成形过程有限元仿真以及触变成形过程工艺调控和变形强韧化机理。通过项目研究，实现高熵合金半固态坯料的制备及其触变成形，为高熵合金高质量构件的成形制造提供技术支撑，促进高熵合金在工业领域中进一步应用。

To solve the technical bottleneck problem such as high resistance to deformation and difficult forming of structure component, we propose a novel method named “mechanical alloying-hot pressing density-isothermal temperature globularization” in which prealloyed powder, bulk billet and semisolid billet of high entropy alloy (HEA) are fabricated by mechanical alloying, hot pressing and semisolid state isothermal treatment, respectively. Furthermore, this novel method is employed in thixoforming of HEA to realize near net shape of HEA structure component. The main research contents involve adjustment and control of process parameters, microstructure and properties of prealloyed powder of HEA fabricated by mechanical alloying, process optimization and density mechanism of bulk HEA during hot pressing, microstructure evolution of semisolid microstructure of HEA, rheology of HEA in semisolid state, finite element simulation of thixoforming of HEA, process optimization and deformation mechanism of HEA during thixoforming. It is aiming to realize fabrication and thixoforming of HEA, provide a technical support to forming manufacture of HEA strucuture component, and promote further application of HEA to industry field.