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本文研究激光快速熔凝对一种新型Ni基铸造超合金显微组织和磨蚀磨损性能的影响。高Mo,W含量Ni基铸造合金是一种具有低膨胀系数和耐磨耐蚀等特种工程性能的新型材料。因合金中难熔重元素含量较高(33wt-％Mo,17wt-％W),其铸造组织粗大,含有大量高熔点相,并存在严重偏析。用高能量密度激光快速熔凝表面处理之后,合金组织发生显著改变。全部高熔点相熔化,明显提高固溶度;结晶组织细化,分别为精细枝晶、胞状枝晶、胞状晶和平面凝固组织;熔区内合金元素均匀分布,基本消除偏析。合金组织变化使其性能进一步改善,熔区硬度明显增加,提高了抗磨擦磨损和在酸性介质中的耐磨蚀性能。
In this paper, the effect of laser rapid solidification on the microstructure and abrasive wear properties of a novel Ni-based foundry superalloy was investigated. High Mo, W content Ni-based cast alloy is a new material with a low coefficient of expansion and wear-resistant corrosion and other special engineering properties. Due to the high content of refractory heavy elements (33wt-% Mo, 17wt-% W), the castings are coarse and contain a lot of high melting point phases with serious segregation. After rapid surface melting with high energy density laser, the alloy structure changes significantly. All the high melting point phase melting, significantly improve the solid solubility; refined crystal structure, respectively, fine dendrites, dendrites, cellular crystal and plane solidified structure; molten zone alloy elements evenly distributed, the basic elimination of segregation. Changes in the alloy structure to further improve its performance, the melting zone hardness increased significantly increased wear resistance and abrasion resistance in acid medium.