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脉冲激光辐照ZrO2涂层的18—8不锈钢快产组织与精细结构 总被引:1,自引:0,他引:1
利用脉冲激光辐凿穿超高温度梯度下表层预置ZrO2纳米颗粒涂层的18-8奥氏体不锈钢的快凝组织形态、微结构特征及力学性质。结果表明:在表层约15μm范围内形成Zr的合金化微区。Zr最大含量(原子分数)为43.3%,但Zr成分分布存在不连续特征;预置纳米ZrO2陶瓷涂层明显提高了激光作用深眼高温国度梯度和高冷办经了快凝亚组织并得到超细枝晶及胞晶。并观察到位错胞及栅栏孪晶两类亚晶,而激光熔区的外延生长机 相似文献
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激光合金化Ni-W-Si涂层的组织与性能研究 总被引:1,自引:0,他引:1
以Ni-W-Si合金为原料,利用激光合金化技术在AISI 304不锈钢表面上制备了以W_5Si_3的复合相为增强相的Ni-W-Si涂层,用SEM、XRD与EDS等方法分析了合金的显微组织、相组成及成分,讨论了不同W、Si含量对涂层组织和耐磨性能的影响。结果表明,涂层中析出了大量花瓣状或胞状W_5Si_3、CrSi_2及(Fe,Ni)复合相,对提高涂层抗磨损能力有良好的增强作用;含W量较高的粉末经激光合金化后残余大量未熔W颗粒,新相以其为形核中心析出并长大形成夹心结构;涂层磨损机制主要为磨粒磨损,高强韧的W_5Si_3相使涂层的显微硬度显著提高(最高达10400 MPa),并使室温干滑动摩擦磨损抗性提高了3~8倍。 相似文献
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通过研究微量合金元素W(<2.0at%)添加下,电沉积Ni-W镀层表面形貌、微观组织和力学性能的变化,探索了材料制备工艺与微合金化对改善Ni-W镀层组织、进一步提高力学性能的内在机制.结果表明,Ni-W镀层为单相fce结构,随着W含量的增加,镀层表面从粗大的棱锥界面沟槽转变为均匀分布的微孔,同时表面粗糙度和晶粒尺寸逐渐... 相似文献
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目的提高材料的表面性能和开拓非晶涂层的应用。方法将Fe-Cr-Si-P非晶态合金粉末预涂覆于304L不锈钢基材表面,采用宽带激光熔覆技术制备非晶涂层。通过光学显微镜和扫描电镜分析涂层的微观组织结构和界面组织特征。采用FLUENT软件建立宽带激光熔覆的流场模型,并模拟激光熔池内的流场分布。结果涂层组织具有明显的分层结构,涂层界面区为平面晶和外延树枝晶,涂层中部区域为大面积非晶区,涂层表面为等轴树枝晶,且界面外延生长层的高度随激光扫描速度的增大而减小。激光熔池的流动为对流机制,熔体流动速度在熔池中部出现了低谷,最大速度出现在熔池表面,在熔池下部流体也会出现一个速度峰值。峰值距熔池底端的距离随着扫描速度的增加而减小。结论宽带激光熔覆的Fe-Cr-Si-P涂层由非晶和树枝晶结晶相组成,涂层组织为分层结构。熔池底部峰值距熔池底端的距离随着扫描速度的增加而减小,且与外延生长层厚度的实测距离基本吻合。建立了激光工艺参数与外延生长层厚度的关系模型,为宽带激光熔覆大面积非晶涂层的可控制备提供了理论依据。 相似文献
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TiAl合金激光气体合金化 总被引:6,自引:0,他引:6
本文利用激光气体合金技术对TiAl合金进行表面改性,制得了以TiN为增强相的新型快速凝固“原位”耐磨复合材料表面改性层,激光表面改性层显微组织受激光处理工艺参数的控制,试验结果表明,激光气体合化是一种提高TiAl合金耐磨性的表面改性新技术。 相似文献
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机械合金化法制备Fe—Ni—P—B磁性非晶合金的研究 总被引:6,自引:0,他引:6
用机械合金化法研究制备Fe-Ni-P-B系磁性非晶材料,用X射线衍射仪,扫描电子显微术和透射电子显微术对不同球磨工艺处理的Fe40Ni40P14B6成分的粉末进行了分析,结果表明,成分为Fe40Ni40P14B6的粉末,可通过机械合金化使其非晶化。 相似文献
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研究了低碳钢表面Cr-Ni激光合金化工艺,并对处理后的合金层组织与性能进行了测试分析。结果表明,Cr-Ni激光合金化可获得一特殊的显微组织形态,它不但具有高的硬度,而且有着极强的耐蚀性,由于激光的作用,使低碳钢的基体也产生了一定的强化效果。 相似文献
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MA Xueming YANG Yuanzheng DONG Yuanda HE Yizhen Institute of Solid State Physics Academia Sinica Hefei China 《金属学报(英文版)》1992,5(10):323-326
The amorphization transformation of Al-Y-Ni system by mechanical alloying was inves-tigated in both thermodynamic and kinetic aspects.The amorphous powder of Al-richcomposition Al_(80)Y_(15)Ni_5 was formed after 70 h milling.The process of the amorphiza-tion was monitored by X-ray diffraction.The dependence of the amorphization on themilling intensity was also discussed.The results show that over milling with extra-highintensity has an unfavourable effect on amorphization of the system. 相似文献
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ZHANG Jianqiang WU Bingyao Southeast University Nanjing China WU Hiaohua WANG Guiqin ZHAO Jiwan Nanjing University China 《金属学报(英文版)》1995,8(3):215-218
STUDYOFAMORPHOUSFe-Zr-B-(Cu)ALLOYSBYMECHANICALALLOYING¥ZHANGJianqiang;WUBingyaoSoutheastUniversity,Nanjing,ChinaWUHiaohua;WAN... 相似文献
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PREPARATIONOFAMORPHOUSMo_5Si_3BYMECHANICALALLOYINGANDTHECRYSTALLIZATIONLiMingwei;TangRenzheng;LiWenxian(DepartmentofMaterialsS... 相似文献
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Wei Lumei Deng Liyan Department of Mechanical Engineering Guangxi University of Technology Liuzhou P. R. China 《中国有色金属学会会刊》1998,(3)
1INTRODUCTIONLaseraloyingtreatmentmakeslaserbeamheat,andmeltorsolidifymetalsurfacequicklybyheatingconductioninitsownbody.Duet... 相似文献
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L. Zhuang K.H. Wong Department of Applied Physics The Hong Kong Polytechnic University Kowloon Ho ng Kong China 《金属学报(英文版)》2005,18(3):237-241
1.IntroductionZnO isa novelphotonic m aterialw ith the propertiessim ilarto those ofG aN.ZnO isofhexagonalw urtzite-type structure w ith a direct w ide band gap of3.3eV and an excitonic binding energy of ̄60m eV,m uch largerthan ̄25m eV ofG aN[1,2].Thispe… 相似文献
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C. Dong A.M. Wu S.Z. HaoState Key Lab. for Materials Modification by Laser Ion Electron Beams Dalian University of Technology Dalian ChinaA.M. Zhang T. XuState Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics The Chinese Academy of Sciences Lanzhou ChinaJ. Xu H. W. Liu Z.R. ZhouTribology Research Institute Southwest Jiaotong University. Chengdu China 《金属学报(英文版)》2003,16(4):276-282
The present paper reports the rapid surface alloying induced by the bombardment of high-current pulsed electron beam. Two kinds of substrate materials were examined to show this effect. The first sample was a pure Al metal pre-coated with fine carbon powders prior to the bombardment, and the second alloy is the D2-Crl2MolVl mould steel pre-coated with Cr, Ti, and TiN powders. The surface elements diffuse about several micrometers into the substrate materials only after several bombardments. Tribological behaviors of these samples were characterized and significant improvement in wear resistance was found. Finally, a TEM analysis reveals the presence of stress waves generated by coupled thermal and stress fields, which was considered as the main cause of the enhanced properties. 相似文献