Structural characterization and property of in-situ synthesized AZ91-Mg2Si composite

A new-type Mg2Si composite was prepared with Mg-9Al-1Zn （AZ91） alloy and vermiculite as raw materials by melt infiltration method. The results show that the microstructure of composite consists of a large amount of MgESi precipitates and a little amount of MgO embedded in α-Mg matrix. The Vickers hardness of the composite is obviously higher than that of matrix of AZ91 alloy. Moreover, the composite exhibits excellent compressive property. The ultimate compressive strength of the material is 290 MPa, the yield strength is 175 MPa, and the elongation is about 5%, which are higher than those of AZ91 alloy.     

Gadolinium solubility and precipitate identification in Mg-Gd binary alloy

Gadolinium (Gd) solubility in magnesium (Mg) matrix and precipitate composition in Mg-Gd binary alloys were investigated. The alloys containing different Gd contents (10wt.%-35wt.%) were employed to identify Gd solubility after annealing at different temperatures. It was confirmed that the maximum Gd solubility was 22.8wt.% at 550℃ based on the regression analysis method. Mg5+xGd (0相似文献   

Microstructure and mechanical properties of Mg-6A1-4RE-0.4Mn alloy

Mg-6Al--4RE-0.4Mn （mass fraction, %, RE=Ce rich mischmetal） alloy was prepared by steel mould casting technique. Solid solution and artificial aging （T6） were carried out. The microstructure and mechanical properties of both as-cast and T6 treated alloys were investigated at room temperature and 423 K. It is found that the intermetallic compounds of the as-cast and T6 treated alloys were mainly composed of Al11RE3, Mg17Al12 and Al6REMn6. The Vickers hardness （Hv） of the as-cast alloy is 63 and it increases to 70 after T6 heat treatment. T6 heat treatment plays a slight role in the tensile properties at room temperature, but the yield strength and elongation of T6 state at 423 K are distinctly improved. The yield strength and elongation of the as-cast alloy at 423 K are 71 MPa and 18%, respectively, and the values increase after T6 heat treatment, which is attributed to Al11RE3, Mg17Al12 and Al6REMn6 precipitates that impede the dislocation movement and gliding of grain boundaries effectively.     

Microstructures and Properties of Melt-Spun and As-Cast Mg-20Gd Binary Alloy

Mg-20Gd（ %, mass fraction）samples were prepared using melt-spinning and copper mold casting techniques. Microstructures and properties of the Mg-20Gd were investigated. Results show that the melt-spun ribbon is mainly composed of supersaturated a-Mg solid solution phase and the as-cast ingot mainly contains a-Mg solid solution and MgsGd phase. The differential scanning calorimeter （DSC） curve of the ribbon exhibits a small exothermic peak in the temperature range from 630 to 680 K, which indicates that the ribbon contains a metastable phase （amorphous）. Tensile strength at room temperature of the melt-spun ribbon and as-cast specimen are 308 and 254 MPa, respectively. The elongations of the two samples are less than 2 %. The fracture surfaces demonstrate that the fracture mode of the as-cast Mg-20Gd is a typical cleavage fracture and that of the melt-spun sample is a combination of brittle fracture and ductile fracture.     

Ti_(45)Cu_(35)Zr_8Ni_7Pd_5块体非晶合金的形成能力及力学性能(英文)

利用铜模铸造方法制备了Ti45Cu35Zr8Ni7Pd5合金圆棒。通过XRD、SEM和DSC等手段研究了合金的组织,讨论了合金的玻璃形成能力,测定了合金的力学性能。结果表明,直径为2mm的圆棒为单一金属玻璃相,3mm和4mm直径的圆棒由金属玻璃相和TiCu结晶相组成。直径为2mm的圆棒具有最高的压缩断裂强度(2160MPa)和最高的硬度(维氏硬度,5600MPa)。压缩强度和硬度随着圆棒直径的增加而降低,但变形能力增加。     

CYJ10-3-53HB抽油机平衡度的设计

随着油田新的勘探开发需要,原来的抽油机在某些方面已经不能满足要求.一方面是由于油井开采的条件越来越恶劣,另一方面是油田对节能减排的要求越来越高.比如油田对抽油机提出了“三个最大”的需要,即在最大冲程、额定载荷、减速器额定扭矩下,抽油机的平衡度要满足要求.通过对抽油机的平衡度分析计算,同时引进新的设计理念,学习和借鉴新结构新思路,重新研制了CYJ10-3-53HB抽油机,使抽油机更加人性化、能最大限度地满足平衡度的要求,现场试验表明CYJ10-3-53HB抽油机比以往的常规10型机具有较大的平衡扭矩,能够彻底解决目前平衡度不达标的问题.同时又具有结构简洁、安全性能好、操作维护方面、节电效果好等优点.     

Mg-Li-RE系合金研究进展

在简要介绍高强轻质Mg-Li合金发展历史的基础上,对Mg-Li合金中含稀土(RE)的Mg-Li-RE系合金的研究情况进行总结。重点介绍Mg-Li-RE三元合金以及含RE的Mg-Li其他系合金的研究进展,叙述了RE对Mg-Li合金结构、性能的影响,指出目前存在的问题,提出下一步工作重点和今后的发展方向。     

说病

生病对于我们每个人来说，是件非常倒霉的事，但是每个人都有过生病的经历，或许在将来的某一天，我们当中的所有人会在一场大病中丢失自己的生命。我曾经在火车上听过这么一个故事：香港有位作家的隔壁住着一位妙龄女人。一天早晨，女人起床梳妆打扮之后，想起这两天一直咳嗽，准备吃药时，觉得清晨起来一直没咳过，心想西药吃多了对身体没好处，于是急忙出门赶去上班。当她下楼后，     

泡沫镁的研究进展

介绍了泡沫镁的几种制备工艺，并对各个工艺的优缺点进行了评价。简要概述了泡沫镁的各种性能及应用，最后提出了泡沫镁的发展方向。