本发明属于粉末冶金技术领域，特别提供了一种金属材料的烧结致密化及晶粒尺寸控制方法。利用晶界扩散和晶界迁移动力学的差异来抑制最终阶段晶粒的长大。以纳米/亚微米级难熔金属粉末作为原料，首先对原料粉末进行预处理，并通过喷雾造粒制备钨团聚体，接着进行压制和冷等静压成形，然后采用两步烧结工艺来制备高致密度细晶粒难熔金属。第一步烧结是将压坯快速升温至一个较高的温度T，短时间保温后立即降温至较低温度T2。由于该方法采用无压烧结，解决了难熔金属传统烧结过程中最后阶段晶粒的加速长大，有助于提高晶粒的均匀性，抑制异常晶粒长大。能够制备出接近全致密的钨制品，致密度大于99%，而且能够实现难熔金属制品的近终成形。是一种低成本制备细晶难熔金属的方法，同样也适用于其他金属材料。

The invention belongs to the technical field of powder metallurgy, and in particular provides a method for sintering and densification of metal materials and crystal grain size control. The difference between the kinetics of grain boundary diffusion and grain boundary migration is used to suppress the growth of grains in the final stage. Using nano/submicron refractory metal powder as raw material, the raw material powder is pretreated first, and tungsten agglomerates are prepared by spray granulation, followed by pressing and cold isostatic pressing, and then a two-step sintering process is used to prepare high Dense, fine-grained, refractory metal. The first step of sintering is to quickly raise the temperature of the compact to a higher temperature T, and immediately lower the temperature to a lower temperature T2 after holding it for a short time. Because the method adopts pressureless sintering, it solves the accelerated growth of crystal grains in the final stage of the traditional sintering process of refractory metals, helps to improve the uniformity of crystal grains, and inhibits abnormal grain growth. It can prepare nearly fully dense tungsten products with a density greater than 99%, and can achieve near-final forming of refractory metal products. It is a low-cost method for preparing fine-grained refractory metals, and it is also suitable for other metal materials.