稀土微合金化对Cu-Al共析合金粉末凝固成形作用机理研究

项目名称： 稀土微合金化对Cu-Al共析合金粉末凝固成形作用机理研究

项目编号： No.50804019

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 李文生

作者单位： 兰州理工大学

项目金额： 21万元

中文摘要： 用铜铝合金粉未制备表面减摩耐磨层和实施表面修复具有诱人的前景,但铝及铜铝合金亲氧，粉末成形性差、涂（熔）敷层孔隙率高等限制了该类材料在表面工程技术中的应用。开发了一种对克服钣金镜面制品出现表面划痕、滑伤、拉裂等有良好效果的新型高铝（≈14 wt. %）过共析铝青铜粉末材料，研究了在该种新型过共析铝青铜粉末中添加稀土元素Ce后对粉末制备、粉末喷涂及喷涂涂层组织的贡献及影响。 采用共装法一次快速熔炼，铝预脱氧和稀土终脱氧联合工艺措施可以获得含气检验合格的合金液，并使稀土Ce烧损量控制在8-15%之间。稀土Ce对合金有良好的脱氧、除氢和除渣作用，净化合金液。 稀土Ce的加入使粉末粒度分布相对集中，显微硬度平均值可达534HV。Ce的加入使涂层中金属间化合物由FeAl 转变为Fe3Al，含Ce喷涂层中的堆垛层错提高了其机械性能。稀土Ce使基体与熔覆层之间的过渡层明显增宽，在过渡层与熔覆层结合面上具有方向性的柱状组织增多，形成组织致密的冶金熔合区。含Ce 0.1%的共析铝青铜等离子喷涂层减摩、耐磨性能较好，含Ce0.6%涂层中Fe元素及k相增多，摩擦磨损性能下降。

中文关键词： 稀土；作用机理；共析Cu-Al合金粉未；凝固；组织

英文摘要： Usage of Al and Cu-Al powder in surface engineering are limited by oxygenphile, low forming ability and high air holes in coatings，althrouth the foreground of Cu-Al alloy powder to be used in low friction coefficient wear resistent coating and surface mending is bright. A novel Cu-Al eutectoid bronze alloy consisting of 14wt.%Al. It is insensitive to volumetric wear in lubricated sliding contact with stainless steel sheet materials. In this project, effects of Rare Earth Ce to the powders preparation, powders thermal spraying process and coating structures were investigated. A jointly-charging one-melted technique was used to acquire the low gas involved eligible molten alloy, and contribute a low Rare Earth Ce envelopment of 8-15% during the alloy melting. Rare Earth Ce purring and refining the molten metal from O and H gas extraction and enclosure inspiration. The shape of atomized Cu-Al eutectoid bronze powders was more spherical and the hardness was improved to 534 HV by addition of 0. 6 % Ce. With a little bit of Rare Earth Ce added, the well distributed matrix and promotion of diffusion leads to the improvement in bond strength between the coating and the matrix. Cu-Fe new phase has been observed decorating the Fe-Al intermetallics in the Ce added coatings. The Ce has been found to stimulate the transition of the Fe-containing intermetiallics from FeAl to Fe3Al. Stacking faults were observed in the coating with Ce addition, which is responsible for the reduced wear rate and increase of the strengthening. The Cu-Al eutectoid plasma sprayed coatings with 0.1% Ce processes better friction and wear properties then the coatings with 0.6% Ce. For there are more Fe and rougher κhases (Fe3Al) formed on the surface of the coatings with 0.6% Ce, thus impairment the friction and wear properties of the coating due to the adhesion of Fe and Fe3Al intermetiallics to the ferrous based counterparts.

英文关键词： Rare Earth; Action Mechanism; Eutectoid Cu-Al Alloy Powder; Solidification; Microstructure