The present study involves the investigation on the effect of processing parameters of powder metallurgy on the microstructure and hardness characteristics of the green as well as sintered specimens of magnesium. The processing parameters include the high-energy ball milling time, compaction pressure, and sintering temperature. From SEM images of 1, 3, and 5 h ball-milled powders, it is revealed that the sequence of change of morphology and size of particles is: flattening (formation of lamellas), fracturing (cracking of lamellas), and dynamic balance (adherence of a small particle with other particles and fracturing), respectively. The average particle size decreases with increasing ball milling time. 0, 1, 3, and 5 h ball-milled powders are compacted at different pressures. It is found that green density of the compacts of ball-milled powders depends on the morphology of powder particles, particle size, and compaction pressure. The selected samples were sintered at 500, 550, and 600 °C for 1 h. SEM characterization indicates that grain growth occurs with increasing sintering temperature. With constant mass, the sintering theory indicates that grain growth of larger particles takes place at the expense of smaller particles due to the difference of surface curvature. The density and hardness of sintered samples were calculated by using Archimedes principle and Vickers hardness tester, respectively.

本研究涉及对粉末冶金工艺参数对生坯以及烧结镁试样的显微组织和硬度特性的影响的研究。加工参数包括高能球磨时间，压实压力和烧结温度。从1、3和5 h球磨粉的SEM图像中可以看出，颗粒形态和尺寸变化的顺序为：变平（薄片形成），破裂（薄片破裂）和动态平衡（小颗粒与其他颗粒的粘附和压裂）。平均粒径随着球磨时间的增加而减小。0、1、3和5 h球磨粉在不同压力下压实。发现球磨粉末的压坯的生坯密度取决于粉末颗粒的形态，粒度和压实压力。选定的样品在500、550和600°C下烧结1小时。SEM表征表明，随着烧结温度的升高，晶粒长大。在质量恒定的情况下，烧结理论表明，由于表面曲率的差异，较大颗粒的晶粒长大以较小颗粒为代价。分别使用阿基米德原理和维氏硬度计来计算烧结样品的密度和硬度。SEM表征表明，随着烧结温度的升高，晶粒长大。在质量恒定的情况下，烧结理论表明，由于表面曲率的差异，较大颗粒的晶粒长大以较小颗粒为代价。分别使用阿基米德原理和维氏硬度计计算烧结样品的密度和硬度。SEM表征表明，随着烧结温度的升高，晶粒长大。在质量恒定的情况下，烧结理论表明，由于表面曲率的差异，较大颗粒的晶粒长大以较小颗粒为代价。分别使用阿基米德原理和维氏硬度计计算烧结样品的密度和硬度。