Zn对粉末冶金法制备Mg-Zn合金组织与性能的影响（英文）

Effect of Zn on Microstructures and Properties of Mg-Zn Alloys Prepared by Powder Metallurgy Method

以Mg粉和Zn粉为初始原料,采用粉末冶金技术制备Mg-Zn合金。研究了Zn含量对Mg-Zn合金烧结密度、显微组织、物相组成、弯曲强度和显微硬度的影响。测量了Mg-Zn合金的耐腐蚀性,探讨了Zn元素在粉末冶金过程中的作用机理。结果表明,添加Zn元素后,烧结产物的晶粒细小,烧结密度提高。此外,随着Zn含量的增加,烧结产物的致密度持续增加。XRD分析表明Mg-3%Zn(质量分数)合金主要由α-Mg相组成,而Mg-4%Zn合金由α-Mg和MgZn_2两相组成。随着Zn含量的增加,Mg-Zn合金的抗弯曲强度先增加而后降低,但是显微硬度(HV)持续增加。Mg-3%Zn合金的抗弯强度为123.6 MPa,显微硬度为1017 MPa,分别比纯Mg样品高出58%和45%。耐腐蚀性能测试表明当添加Zn元素后,Mg-Zn合金的腐蚀速率降低,Mg-3%Zn合金具有最低的腐蚀速率和最佳的耐腐蚀性能。

Mg-Zn alloys were prepared by a powder metallurgy method using Mg powder and Zn powder as starting materials. The effects of the Zn content on sintering density, microstructure, phase composition, bending properties and micro-hardness of the Mg-Zn alloys were studied. The corrosion resistance of the Mg-Zn alloys was also measured. The function mechanism of Zn element during the powder metallurgy process was analyzed. Results show that the sintered compacts have finer grain size and higher sintered density upon Zn addition. The density of the sintered products increases with the increasing of Zn content. XRD analysis shows that the Mg-3 wt% Zn alloy is mainly composed of α-Mg phase. When the content of Zn is 4 wt%, the Mg-Zn alloys is composed of α-Mg and MgZn2 phases. With the increase of the Zn content, the bending strength of the Mg-Zn alloys first increases and then decreases, but the micro-hardness HV of Mg-Zn alloys always increases. The bending strength and micro-hardness of Mg-3 wt% Zn alloys are 123.6 MPa and 1017 MPa, respectively, which are 58% and 45% higher than those of pure Mg samples. Corrosion resistance measurements show that the corrosion rate of the Mg-Zn alloys decreases with the addition of Zn element, and the Mg-3wt% Zn alloy shows the lowest corrosion rate and the best corrosion resistance.