Laser surface coating of Fe-Cr-Mo-Y-B-C bulk metallic glass composition on AISI 4140 steel
Laser surface coating of Fe-Cr-Mo-Y-B-C bulk metallic glass composition on AISI 4140 steel
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DOI：
10.1016/j.surfcoat.2007.09.028
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发表时间：
2008-03-15
影响因子：
5.4
通讯作者：
Dahotre, Narendra B.
中科院分区：
文献类型：
--
作者：
Basu, A.;Sarnant, A. N.;Dahotre, Narendra B.
铁基大块非晶合金具有很高的硬度、弹性模量/极限和耐磨/耐腐蚀性能。在本研究中，已作出了尝试，开发了一种非晶涂层与Fe 48 Cr 15 Mo 14 Y 2C 15 B6块体金属玻璃在AISI 4140基板上的激光表面处理。采用扫描电镜和X射线衍射分析了涂层的微观结构和相聚集情况。采用维氏显微硬度计和球-板磨损试验机分别测试了涂层的显微硬度和耐磨性。涂层厚度与入射激光功率和作用时间成正比。尽管试验范围广泛的工艺参数，目前的实验是无法保留完整的非晶表面微观结构后，激光表面涂层。数值预测的热剖面和相关参数表明，冷却速率和涂层区经历的热梯度是相当高的。然而，未能保持非晶/玻璃态微观结构的，否则散装金属玻璃态合金表明，组成的变化（溶质再分配）内的涂层区和整个涂层-基材界面是负责从熔体的结晶相的成核和生长。然而，涂层参数和表面显微组织和性能之间的相关性允许确定最佳条件，确保细晶粒均匀的显微组织与硬度和耐磨性的显着改善。(C)2007 Elsevier B. V.保留所有权利。
Fe-based bulk metallic glasses exhibit very high hardness, elastic modulus/limit and wear/corrosion resistance. In the present investigation, an attempt has been made to develop an amorphous coating with Fe48Cr15MO14Y2C15B6 bulk metallic glass on AISI 4140 substrate by laser surface processing. Following coating, the microstructure and phase aggregate were analyzed by scanning electron microscope and X-ray diffraction, respectively. Microhardness and wear resistance were assessed using Vickers microhardness tester and ball-on-plate wear testing machine, respectively. The coating thickness varied directly with incident laser power and interaction time. Despite trials with wide range of process parameters, the present experiments were unable to retain complete amorphous surface microstructure after laser surface coating. Numerical prediction of the thermal profile and related parameters suggest that the cooling rate and thermal gradient experienced by the coated zone were fairly high. Yet failure to retain amorphous/glassy microstructure of an otherwise bulk metallic glassy alloy suggests that compositional changes (solute redistribution) within the coated zone and across the coating-substrate interface are responsible for nucleation and growth of crystalline phases from the melt. However, correlation between coating parameters and surface microstructure and properties allowed determination of the optimum conditions that ensured fine grained uniform microstructure with a significant improvement in hardness and wear resistance. (C) 2007 Elsevier B.V. All rights reserved.