Y含量对Mg-Al-Zn堆焊合金摩擦磨损性能的影响

Effects of Yttrium Addition on the Wear Resistance of Surfacing Welding Mg-Al-Zn Alloy

摘要:

堆焊作为一种传统的表面修复技术,可对镁合金构件表面出现的局部损伤进行有效地修复,提高其性能及使用寿命。研究了Y元素添加及其含量对AZ91焊丝堆焊合金常温下干滑动摩擦磨损性能及磨损机制的影响。结果表明：由于存在粗大β-Mg₁₇Al₁₂相,未添加稀土Y元素的AZ91堆焊合金的耐磨性能较差；通过添加稀土Y元素,可以减少粗大β相的尺寸和数量,减小亚表层变形层的厚度以及堆焊合金发生剥层磨损的程度,提高堆焊合金的耐磨性；稀土Y元素会导致堆焊合金的硬度降低；AZ91堆焊合金的主要磨损机制有三种：磨粒磨损、氧化磨损和剥层磨损

Abstract:

The surfacing welding is the common repairing technology and an effective way for the repair of local damage occurs at the magnesium equipment surfaces. The effects of varying contents of the yttrium on the dry sliding wear behavior of surfacing AZ91 magnesium alloys were investigated in this work. The results demonstrated that the surfacing AZ91 alloy without yttrium addition exhibited poor wear resistance, due to the massive intermetallic β- Mg₁₇Al₁₂ phases. With the addition of yttrium, wear resistance was improved resulting from the decrease of size and quantity of the β phase, which reduced the alloy hardness and decreased the subsurface metal deformation degree caused by friction. Three primary wear mechanisms were observed: abrasion, oxidation and delamination.