共查询到19条相似文献,搜索用时 93 毫秒
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塑性变形对渗钛过程的影响 总被引:1,自引:0,他引:1
用正交试验方法对16Mn钢形变渗钛过程进行了探讨。根据实验结果分别讨论了温度,时间,形变量参渗钛过程的影响规律,实验结果表明预先室温塑性变形对置换原子钛的渗入的渗入有促进作用,存在一个最佳形变量。 相似文献
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纯铜双层辉光离子渗钛高温氧化性能的研究 总被引:6,自引:0,他引:6
采用双层辉光离子渗金属技术,在纯铜表面形成均匀的渗钛层.对离子渗钛试样和纯铜试样在400℃和700℃进行了高温氧化对比实验,分别给出了它们的氧化动力学曲线,用扫描电子显微镜观察分析氧化表面形貌,结果表明纯铜表面离子渗钛后提高了高温抗氧化的性能,降低了氧化速率,离子渗钛层的氧化膜致密,对继续氧化有阻碍作用。 相似文献
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固体法渗钛机理的探讨 总被引:2,自引:0,他引:2
对T8钢,45钢,Cr12MoV钢试样进行了渗钛实验,用光学显微镜,X射线衍射仪及电子探针等对渗层形态,结构及微区万分进行了分析,对渗层的形成机理进行了探讨。认为在被覆碳化钛过程中,渗剂中残留的氧化性气氛,反应过程中产生的废气严重危害渗层的形成,文中提出的软密封方法可有效地防止氧化并能及时排除反应中产生的废气,使上述三种材料均能稳定获得8-10μm渗层。 相似文献
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用粉末法对20、45钢进行铝钛共渗,结果表明,采用双层密封比单层密封能获取更厚的渗层,此外,当以TiO_2为供钛剂时,AlF_3是适宜的活化剂,而以Ti粉为供钛剂时,NH_4F比AlF_3更好,在共渗剂中掺入稀土可使渗层厚度增加30%以上,稀土的催渗效果与扩渗温度和稀土掺入量等有关。 相似文献
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DIFFUSION TITANIZING is applied to increase thedurability of tools,which operate under wearconditions[1].There is considerable bibliographicaldata concerning the diffusion titanizing process,inparticular,problems connected with hard titaniumcarbide layers are quite well elaborated[2-4].In this paper,a novel vacuum titanizing process,which involves treating steel in titanium vapor at thetemperature over1000°C under low pressure,has beenproposed[5].A porous material containing titaniumw… 相似文献
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Up to now, the aluminide coatings used to protect industrial components at high temperature and corrosive environments have been modified by Pt, Cr, Si and Ni. In this investigation, aluminide coatings were modified by titanium and the microstructural feature and formation mechanism were evaluated. The coatings were formed on a Ni-based superalloy(IN738LC) by a two stage process including titanizing at first and aluminizing thereafter. Pack cementation titanizing performed at temperatures 950℃ and 1050℃ in several mixtures of Ti, Al2O3 and NH4Cl. At the second stage,aluminum diffused into surface of the specimens by an industrial aluminizing process known as Elcoatl01(4 hrs at 1050℃C). The modified coatings were characterized by means of standard optical microscopy, scanning electron microscopy,energy dispersive spectroscopy and X-Ray diffraction methods. The results show that Ti in the coatings is mainly present in the form of TiNi and Al67CrsTi25. Titanium modified coatings grew with a mechanism similar to simple aluminizing; this includes inward diffusion of Al from the pack to the substrate and then outward diffusion of Ni from the substrate to the coating. The advantages and characteristics of this two-stage modified coating is discussed and the process parameters are proposed to obtain a coating of optimum microstructure. 相似文献
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为了提高纯铜表面的耐磨性能,采用电镀/浆料包渗相结合的方法,以TiO2粉为渗Ti源,纯Al粉为还原剂,在Cu表面预镀Ni随后表面浆料包渗Ti-Al,制备Ti-Al共渗层。研究了包渗温度对Ti-Al渗层组织和耐磨性能的影响。采用SEM和XRD分析了渗层表面形貌和结构。结果表明:在800~950°C共渗12 h时,随着温度的升高,渗层组织变化过程为NiAl+Ni3(Ti,Al)→NiAl+Ni3(Ti,Al)+Ni4Ti3→Ni4Ti3+NiAl→NiAl+Ni3(Ti,Al)+NiTi;Ti-Al渗层的摩擦因数随着包渗温度的升高而降低,最小摩擦因数约为纯铜的1/3,最小硬度为纯铜的5倍。 相似文献