共查询到19条相似文献,搜索用时 62 毫秒
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<正> 碳钢与铸铁在尿素与硫磺高温分解产物中进行气体硫氮碳三元共渗的过程在有关文献中已有阐述。其中特别指出:这种扩渗气氛能保证渗氮层的浓度稍低于人HBT-12型高氰盐浴中的硫氮碳共渗.因此在研究高速钢硫氮碳共渗的特点时,采用尿素(NH_2)_2CO和硫脲(NH_2)_2CS分解而得的高温分解气氛,其氮势 相似文献
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王声扶 《机械工人(热加工)》1991,(9):43-46
硫氮碳共渗是向钢铁零件表面同时渗入硫、氮、碳三种元素的化学热处理工艺。一般采用的温度是570~580℃。 硫氮碳共渗是一种既古老又年轻的工艺。早期应用的硫氮碳共渗盐浴含有大量的氰根(CN~-),对环境污染严重。为了解决这一问题,近年来发展了所谓“无污染硫氰共渗工艺”,将盐浴含氰量降至0.5%~0.8%,且它的废 相似文献
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探讨了Cr12MoV钢硫氮碳共渗层中硫的渗入深度及渗层表面状态对摩擦系数和耐磨性的影响。 相似文献
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稀土对H13钢在盐浴氮化中的影响 总被引:4,自引:0,他引:4
研究了稀土对H13钢在盐浴氮化中的影响。对H13钢进行低温无毒硫氮碳共渗,在这基础上加入稀土元素,实验结果表明,稀土元素的加入可加速盐浴氮化的过程,具有催渗效果,并能改善其性能,满足模具盐浴氮化的技术要求,具有较好的经济效益和社会效益 相似文献
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High load friction and wear experiments by means of atomic force microscopy were carried out at the surface of highly (0 0 1) oriented vanadium oxide V2O5 thin films deposited on silicon by reactive magnetron sputtering. Microscopic friction coefficient was estimated for wide range of loads. The nature of surface wear due to multiple, high load scanning is presented and discussed. 相似文献
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利用溶胶–凝胶旋涂法和后退火工艺在FTO导电玻璃上制备了钨镍共掺杂V2O5薄膜,研究了薄膜在不同温度和不同偏压下的光电特性和相变特性。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM) 和X射线光电子能谱仪(XPS) 测试了钨镍共掺杂V2O5薄膜的晶体结构、表面形貌和组分,分析了不同钨镍共掺杂浓度对V2O5薄膜相变光电特性的影响。结果表明,当钨和镍的掺杂质量分数分别为3 %和1.5 %时,钨镍共掺杂的V2O5薄膜的相变温度为218.5 ℃,在可见光范围内有较高的透过率,在近红外1310 nm波长处的光学透过率达48.83%,与未掺杂V2O5薄膜的光学透过率相比提高了10.29%,薄膜电阻降低了30.53%,热致回线宽度收窄为15 ℃,说明钨镍共掺杂的V2O5薄膜具有良好的可逆相变光电特性,有望在新型光电器件领域得到较好的应用。 相似文献
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H13模具钢经过热处理可以获得优良的性能,诸如高强度、红硬性及高的冲击韧性值。从解析H13的化学成分入手,对选用高温球化退火、淬火及二次回火做了说明,提供了工艺数据,并在结论中给出了生产实践中获得的五条经验。 相似文献
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Dariush Souri 《Measurement》2011,44(10):2049-2053
The glass-transition temperature (Tg) and crystallization temperature (TCr) have been determined for the system (60 − x)V2O5–xSb2O3–40TeO2 with 0 < x < 10 (in mol%) using differential scanning calorimetry (DSC) at heating rates φ = 3, 6, 9 and 13 K/min. The effect of the heating rate and the Sb2O3 content on Tg is discussed. It was observed that the transition region shifts to higher temperatures when the measuring time is reduced (or, conversely, when the applied temperature rate is increased). Using differential scanning calorimetry, the compositional dependence of Tg has been determined and so, an empirical equation has been deduced which relates the glass-transition temperature with the Sb2O3 content. 相似文献
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在弱还原气氛下制备了单价银离子(Ag+)掺杂的CaO-P2O5系统玻璃,测试了其在室温下的吸收光谱、激发光谱和发射光谱。Ag+-CaO-P2O5玻璃的吸收光谱表明两个吸收峰。高能峰位于220nm波长,由4d10→4d95P1跃迁引起,低能峰中心位于240nm波长,归因于4d10→4d95s1跃迁,该吸收与其发射特性有关。紫外波段的宽带吸收产生了可见波段强烈的荧光发射,发光峰位于440nm波长,半宽度为130nm.研究了掺质浓度与发光特性的关系,随着掺质浓度的增加(0.05~0.25mol%),发光峰向较长波段移动。在Ag2O含量为0.5mol%时,出现了浓度猝灭现象。为了比较起见,同时还研制了Cu+-CaO-P2O5及Cu+-Ag+-CaO-P2O5玻璃。 相似文献
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C.J. Klenke 《Tribology International》1990,23(1)
A recent investigation suggests that selected oxides perform well as additives in molybdenum disulphide (MoS2) because of their ability to soften at asperity contacts with the result that the solid lubricant can attain and retain a preferred tribological orientation.This research determined the effectiveness of boric oxide (B2O3), when used as an additive in MoS2, for substrate temperatures ranging from 21°C to 316°C. This range was used to allow the asperity contact temperature to vary below and above the softening point of B2O3. It was found that a moderate friction coefficient and high wear, which is attributed to the additive acting abrasively, occurred when the asperity contact temperature was well below the softening point of the oxide. When the asperity contact temperature neared the softening point of the oxide, the friction coefficient increased dramatically and wear volume was reduced. It is postulated that B2O3 acted adhesively at the interface resulting in a higher coefficient of friction, and wear decreased due to an attainment of a preferred orientation by the MoS2. For asperity contact temperatures significantly above the softening point of B2O3, the friction coefficient returned to about the same value as for temperatures below the softening point. It is speculated that wear continued to increase moderately because of localized melting of the B2O3, permitting the MoS2 to be removed from the interface. These observations support a hypothesis that an additive, such as boric oxide, can soften as the asperity contact temperature approaches the softening point temperature of the additive so that the overall tribological conditions may be improved resulting in reduced interfacial wear. Significant changes in temperature, load or sliding velocity would, of course, dramatically alter the wear characteristics observed at the interface. 相似文献
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H13热作模具钢稀土硼碳氮多元共渗 总被引:2,自引:0,他引:2
对H13热作模具钢稀土硼碳氮共渗工艺进行了研究,并对其共渗层的组织、硬度及耐磨性和抗氧化性进行了测试与分析,结果表明与碳氮硼共渗工艺相比,稀土硼碳氮共渗层的硬度、耐磨性和抗氧化性明显提高。稀土元素的渗入不仅提高了渗层的硬度、耐磨性和抗氧化性,并且使过渡层的硬度变化减缓,增强了基体与共渗层的结合,为共渗层提供强有力的支撑作用。 相似文献
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