共查询到19条相似文献,搜索用时 656 毫秒
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研究了采用压片预置式激光熔覆工艺,添加适量纳米CeO2颗粒,利用NiCoCrAlY合金粉末在GH4037合金表面激光熔覆制备了纳米CeO2颗粒增强Ni基合金涂层,对熔覆层界面组织进行了显微分析,进行了1000℃高温熔盐热腐蚀性能试验。结果表明,添加适量纳米CeO2颗粒的Ni基合金激光熔覆涂层组织明显细化、致密,裂纹等缺陷得到有效抑制;熔覆层在高温熔盐中腐蚀后出现的隆起和剥落现象轻微,腐蚀层的深度明显减小;纳米CeO2颗粒对Cr2O3膜的碱性溶解有一定的抑制作用;合金的抗高温热腐蚀性能显著提高。 相似文献
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为了研究激光熔覆工艺条件下Fe3Al金属间化合物合金层的组织结构特点,以纯Fe3Al粉 1%Y2O3为原料在钢基体表面激光熔覆Fe3Al金属间化合物,利用扫描电镜、能谱仪、X射线衍射试验方法等对熔覆合金层、合金层与钢基体的结合界面等进行了显微组织与相结构的分析.试验获得了致密、无肉眼可见气孔、夹杂的合金层,合金层与基体间完全冶金结合,但存在裂纹现象;熔覆合金层主要由单相Fe3Al构成,覆层组织为粗大等轴状晶团,等轴状晶团由大量极细小的条状Fe3Al晶粒构成,一些相邻的条状晶粒之间具有基本一致的晶体学取向. 相似文献
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3Cr2W8V钢的激光熔覆镍基硬面合金的耐磨性 总被引:1,自引:1,他引:0
本文报导在钢表面激光熔覆镍基硬面合金表面改性的研究结果,用OM、TEM、XRD研究了合金层的微观组织特征,用EDS-SEM研究了熔覆合金层的成份分布;用相分析,XRD、比色法,化学分析研究了合金层的碳化物(硼化物)种类、数量、分布;还研究了激光熔覆合金层的显微硬度和耐磨性。 相似文献
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多道搭接激光熔覆NiCrBSi合金层组织及性能 总被引:1,自引:0,他引:1
为了改善40Cr钢的表面状态,拓展其应用范围,采用CO2激光器及LASERCELL-1005六轴六联动三维激光加工机床在40Cr钢表面多道搭接激光熔覆了NiCrBSi合金粉末,利用扫描电镜、金相显微镜、磨损试验机、盐雾试验机等对熔覆层的组织及性能进行了研究.结果表明:激光熔覆层由熔覆区、结合区和热影响区3部分组成.多道... 相似文献
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激光熔覆碳化物/金属基复合涂层裂纹的产生与控制 总被引:3,自引:0,他引:3
介绍了控制激光熔覆碳化物/金属基复合涂层裂纹的产生的途径,通过优化激光工艺参数,优选工艺处理条件,合理设计熔覆层成分,改善基体状况来减少裂纹源,减少裂纹的产生。 相似文献
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Microstructure characteristics of Ni-based WC composite coatings by laser induction hybrid rapid cladding 总被引:3,自引:0,他引:3
Shengfeng Zhou Yongjun Huang Xiaoyan Zeng Qianwu Hu 《Materials Science and Engineering: A》2008,480(1-2):564-572
To avoid low cladding rate and cracks of cladding layer, laser induction hybrid rapid cladding (LIHRC) has been put forward in the paper. The microstructure characteristics of Ni-based WC composite coatings at the different laser scanning speed were investigated. For low laser scanning speed, the growth of γ-nickel was characterized by coarse columnar dendrites and eutectics, blocky W2C + Fe3W3C carbides, and bar-like (W, Cr, Ni)23C6 carbides were formed. With increasing laser scanning speed, the growth of γ-nickel presented the fine dendrites and eutectics, the only blocky mixed carbides were precipitated and identified as W2C + FeW3C + W6C2.54 carbides. With further increasing laser scanning speed, the growth of γ-nickel was characterized by cellular crystals and eutectics, the only blocky carbides were identified as W2C + W6C2.54. Moreover, experimental results showed that the efficiency of LIHRC was increased much four times higher than that of laser cladding without preheating, ceramic–metal composite coatings detected were free of cracks and had a good metallurgical bonding with substrate. 相似文献
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Hongxia Wan Dongdong Song Xiaolei Shi Yong Cai Tingting Li Changfeng Chen 《材料科学技术学报》2021,60(1):197-205
High-entropy alloys(HEAs) are of great interest in materials science and engineering communities owing to their unique phase structure.HEAs are constructed with five or more principal alloying elements in equimolar or near-equimolar ratios.Therefore,they can derive their performance from multiple principal elements ratherthan a single element.In this work,three-dimensional printing laser cladding was applied to produce an Al0.4CoCu0.6NiSi0.2Ti0.25 HEA coating.The experimental results confirmed that the laser cladding could be used to produce a thin coating of 120 μm in thickness.In the high-temperature laser cladding process,some Fe elements diffused from the substrate to the coating,forming a combination of face-centred cubic and body-centred cubic phase structures.The HEA coating metallurgically bonded well with the substrate.Owing to the increased dislocation density and number of grain boundaries,the HEA coating was harder and had a stronger hydrophobicity than X70 steel.The electrochemistry results showed that the HEA coating had better corrosion resistance than X70 steel.Aluminium oxides formed on the surface of the HEA coating had a certain protective effect.However,because of the laser cladding,the HEA coating generated cracks.In future work,the laser cladding technology will be improved and heat treatment will be implemented to prevent formation of cracks. 相似文献
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为改善45钢表面的力学性能和耐蚀性,在相同功率下采用不同扫描速率在其表面激光熔覆制备了Ni基(Ni35A)复合涂层。利用金相显微镜、X射线衍射仪、显微硬度计和电化学腐蚀测试系统对熔覆试样进行组织形貌、相组成、显微硬度和耐蚀性能分析。结果表明:熔覆试样由熔覆层、结合区和基体3部分组成;熔覆层组织细密并与基体冶金结合,扫描速率过大时易形成裂纹;熔覆层主要由FeNi3和Ni3B相组成,不同速率所得熔覆层显微硬度均超过400 HV;扫描速率为500 mm/min时熔覆试样自腐蚀电位提高了40 mV。 相似文献
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分析了铸造镍基合金表面激光熔覆层热裂纹产生的原因和特点,探讨了传热变质剂对熔覆层结晶裂纹的抑制作用. 相似文献
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轻量化合金材料的耐高温、抗烧蚀性能较差,采用激光熔覆技术制作涂层的方法可提升其热防护性能。本文从热防护的机理出发,结合激光熔覆工艺对熔覆材料性能的要求,从现有的热防护材料和激光熔覆材料中筛选出几种可实现短时间、无冷却情况下基体热防护的熔覆材料,并对基于激光熔覆工艺的热防护材料的未来发展趋势进行了展望。 相似文献