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The diffusion of La in ε-Fe2~3N(ε)and γ′-Fe4N (γ′)phases pro duced by plasma nitriding was studied. It is found that with increasing nitridin g time, the ε phase continuously decomposes into γ′ one under employed experi mental conditions and compared with γ′ phase or ε+γ′ ones, the mono one ε has an impedient effect on depth of La diffusion. The growth of La layer in dua l phases and mono one follows an approximate exponential law and a parabolic one , respectively, and this kinetics law does not change with increasing temperatur e. The effect of increasing temperature in the range of 520 to 560 ℃ on La d iffusion depth is less than that of phase constitution change such as the decomp osition of ε phase into γ′ one. 相似文献
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本文建立了碳扩散系数与碳浓渡有关、适用于多程快速气体渗碳的渗层碳浓度分布数学模式.利用所得数学模式,进行计算机仿真,与实验结果吻合良好. 相似文献
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离子渗氮层的氮浓度分布函数及计算机仿真 总被引:4,自引:0,他引:4
本文研究了在不同离子渗氮条件下,纯Fe,45,40Cr,42C1Mo和38CrMoAl钢等五种材料离子渗氮层长大动力学的数学模式,在此基础上,利用仿型积分法,推导出离子渗氮层的氮浓度分布函数: C_ε=C_(min)~ε+P_4/ξ_(10)(ξ_1-x)+P_5/ξ_(10)~2(ξ_1-x)~2, C_γ′=C_(min)~γ′+P_1/ξ_(21)(ξ_2-x)+P_2/ξ_(21)~2(ξ_2-x)~2, C_α=C_(min)~α+C_(33)/ξ_(33)~3(ξ_3-x)~3利用上面数学模式,进行计算机仿真,与实验结果符合良好. 相似文献
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Structure and tribological properties of modified layer on 2024 aluminum alloy by plasma-based ion implantation with nitrogen/titanium/carbon 总被引:1,自引:0,他引:1
1 INTRODUCTIONGoodmachinability ,lowdensityandhighspecif icstrengthmakealuminumanditsalloysextensivelybeusedinmanyindustries ,especiallyinaviationandspaceflightindustry .Howeverlowsurfacehardnessandlowwearresistanceoftenlimittheirengineeringapplications .Nitrogenionimplantationintoalu minumanditsalloysoffersthepossibilityofapplica tionswherebothhighwearresistanceandlowdensityarerequired[15] .Moreover ,ourpreviousinvestiga tion[6 ,7] presentedthatwhenaluminumalloywasim plantedwithnitrogen… 相似文献
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介绍了一种新型无辅助阳极式磁过滤器的基本结构,测量了在弯曲弧磁过滤器出口处的离子分布规律。SEM分析表明,无辅助阳极式弯曲弧磁过滤器消除了等离子体中的宏观粒子团。采用无辅助阳极式弯曲弧磁过滤器在玻璃基体上镀铜可以使表面粗糙度Ra从0.44μm降低到0.003μm。 相似文献
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La在脉冲离子渗氮表层中的扩散及其对氮分布和相结构的影响 总被引:6,自引:0,他引:6
研究了在脉冲等离子体稀土渗氮过程中稀土元素La对氮浓度分布和相结构的影响,揭示了La在化合物层中的扩散规律,结果表明:与常规离子渗氮相比稀土绵添加,提高了表面氮浓度,随处理时间的延长而增加,当渗氮时间从2h增加至24h时,化合物导上ε-Fe2-3N(ε)转化为ε-Fe2-3N和γ‘-Fe4N(γ’)双相,此外,La可以扩散进入ε和γ‘相中,La的扩散规律受制于化合物的γ’-Fe4N的比例,随时间延 相似文献
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0 INTRODUCTIONPlasma basedionimplantation (PBII)ofnitrogenisreportedtobeaverycost effectivetechniqueforsurfacemodificationofTi 6Al 4Valloy[1~ 4 ] .Futureworkremainstoconcentrateondeterminingtheexactmechanismofthetechniquewhenappliedtothealloy[2 ] .Forconventiona… 相似文献
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