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PCVD TiN膜基结合强度初探 总被引:1,自引:0,他引:1
等离子体增强化学气相沉积(PCVD)是一项新工艺,特别适合于制备保护复层,不过这项工艺用在模具钢上沉积超硬复层还处于实验研究阶段.如果这种复层能在模具上成功地涂复就可以期望获得外硬内韧的模具,其使用寿命也将大大延长。本文对这个问题进行了探索并取得初步成效。 相似文献
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镁合金微等离子体氧化膜的特性 总被引:81,自引:3,他引:78
采用x射线衍射(XRD)、扫描电镜(SEM)等方法初步研究了镁合金微等离子体氧化膜的相组成及形貌特征。结果表明,该技术能在镁合金表面生长一层厚度大于100μm并与基体结合良好的氧化膜,提高了合金的耐蚀性。在NaAlO2溶液中对MB15镁合金微等离子体氧化时,氧化膜由MgO和MgAl2O4相组成。铝元素已扩散到膜内层,但膜表层存在铝元素富集区。 相似文献
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采用氧气介质阻挡放电(DBD)等离子体处理PBO纤维表面,用以改善PBO纤维与双马来酰亚胺(BMI)树脂之间的界面粘结性能。结果表明,用氧气等离子体处理PBO纤维能大幅度提高PBO/BMI复合材料的层间剪切强度(ILSS)值,最佳处理条件为功率30 W/m3、时间24 s,ILSS值从43.9 MPa提高到62.0 MPa。经过氧气DBD等离子体处理的PBO纤维其表面的氧含量明显提高,氮含量变化不大,甚至在过度处理时降低;官能团-O-C=O基团的含量从0提高到3.16%,-C-O-的含量也明显提高;在氧气DBD等离子体处理后的PBO纤维表面产生大量凹凸不平和沟壑,使纤维表面的粗糙度提高。而表面氧含量的提高和表面形貌与粗糙度的变化,是PBO/BMI复合材料ILSS值提高的重要原因。单丝拉伸实验结果表明,适当的DBD等离子体处理不会对PBO纤维表面产生不良影响,不影响其在复合材料中的作用。 相似文献
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金刚石薄膜电阻率的高低是薄膜绝缘性能优劣的直观反映,也是影响辐射剂量计器件性能的重要因素.针对目前形核工艺与电阻率的关系还不十分清楚的问题.本文研究了微波等离子体形核阶段工艺参数如基片位置、微波功率、甲烷浓度的变化对金刚石薄膜的表面形貌和电阻率的影响.结果表明微波等离子体形核工艺参数对金刚石薄膜的电阻率和表面形貌有显著影响.获得的最佳成核工艺条件:基体温度960℃、甲烷浓度0.72%、压力5.3 kPa、微波功率1300 W.在此工艺条件下制得的金刚石薄膜的电阻率值达到1011 Ω·cm数量级. 相似文献
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为了提高环保型阳极氧化膜的耐蚀性,以氨基乙酸为添加剂,制取镁合金阳极氧化膜.用扫描电子显微镜(SEM)和金相显微镜(OM)观察阳极氧化膜的表面及截面形貌,采用极化曲线(Tafel)和电化学交流阻抗谱(EIS)等电化学方法,检测和评价了镬合金阳极氧化膜的耐蚀性.结果表明:随着氨基乙酸浓度的升高,阳极氧化膜表面趋于平整,孔洞变小,膜表面微观形貌更加连续致密;与不添加氨基乙酸所形成的氧化膜相比,添加了氨基乙酸形成的阳极氧化膜的自腐蚀电位正移,自腐蚀电流变小;当氨基乙酸加入量为7.5 g/L时氧化膜的耐蚀性最优,自腐蚀电流密度为1.18×10~(-7) A/cm~2. 相似文献
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用扫描电子显微镜对沉积在硅油表面的金属铝膜上、下表面的形貌进行了研究 ,证实了液体基底特性对金属铝膜表面形貌的重要影响。 相似文献
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用扫描电子显微镜对沉积在硅油表面的金属铝膜上,下表面的形貌进行了研究,证实了液体基底特性对金属铝膜表面形貌的重要影响。 相似文献
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为了提高聚乳酸(PLA)与铝合金的连接强度,采用在PLA中添加玄武岩纤维(BF)获得BF/PLA复合材料的方式对PLA进行增强。利用转矩流变仪对干燥处理后的PLA及BF进行密炼,利用光纤激光器对铝合金表面进行毛化处理。采用平板硫化机对BF/PLA复合材料和处理后铝合金进行连接成型,测试其拉伸强度,对失效后断面进行分析。结果表明:随着BF质量分数的增加,BF/PLA-铝合金连接强度先增强后降低,BF质量分数的增加影响了BF/PLA复合材料的结晶成核。结合试验获得的结果,建立有限元分析模型进行数值模拟,结果显示所建立的模型能够准确还原BF/PLA-铝合金拉伸过程。 相似文献
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M. Sohi W. J. Poole C. W. Sinclair M. Gallerneault 《Materials Science & Technology》2015,31(4):460-467
AA5xxx aluminium alloys are used in the automotive and packaging industries owing to their high strength and ductility. The addition of Sc and Zr to these alloys has shown promise for improving high temperature stability and therefore broadening the range of applications. This high temperature stability is due to the formation of fine Al3(Sc, Zr) precipitates during aging. In this work, two twin-belt cast Al–3%Mg alloys, one with 0·4% Sc and the other without Sc, were annealed at 300 and 400°C. Hardness, tensile yield stress and electrical resistivity measurements were used to examine the evolution of microstructure and strength of the alloys. These results were then utilised to develop a yield stress–precipitation model to describe simultaneous precipitation hardening and recovery. 相似文献
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Xiaoguang Li Tingting Huang Ang Wei Chong Rui Zhou Yoo Sang Choo Minghui Hong 《光电工程》2017,44(3):340-344
Paint removal from steel structure is executed for shipyards of marine and offshore engineering. Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is proposed as a substituting method. By absorbing high energy of the 1064 nm pulsed laser, the paint is vaporized quickly. The ablated debris is then collected by using a suction pump. Initial metal surface of the steel is exposed when laser beam irradiates perpendicularly and scans over it. The cleaned surface fulfills the requirements of surface preparation standards ISO 8501 of SA2. The adhesion is further characterized with pull-off test after carrying out painting with Jotamastic 87 aluminum paint. The repainting can be embedded onto the laser cleaned surface to bond much more tightly. The excellent adhesion strength of 20 MPa between repainted coating and the substrate is achieved, which is higher than what is required by shipyards applications. 相似文献
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以AZ31镁合金为基体,TiNi形状记忆合金丝为增强体,利用放电等离子烧结法(SPS)制备了TiNi/Mg复合材料,用OM、SEM、EDS对其微观形貌进行表征,并用XRD及DSC研究TiNi丝的相变,同时对该复合材料进行准静态拉伸实验,对其室温及高温力学性能进行研究。结果表明,所制备的TiNi/Mg复合材料中界面处存在Mg、Ti、Ni元素的互扩散现象,并形成宽度约为2 μm的互扩散层;所制备的TiNi/Mg复合材料的高温力学性能高于室温,其中其屈服强度、抗拉强度及弹性模量在100℃时(分别为157 MPa,292 MPa,22 GPa)较室温分别提高了12%、33%和29%,150℃时(分别为143 MPa,251 MPa,20 GPa)较室温分别提高了2%、14%和18%。 相似文献
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强化Mg合金和Mg基复合材料的研究进展 总被引:1,自引:0,他引:1
Mg和Mg合金材料对现代社会发展具有举足轻重的意义.根据近期部分国内外资料并结合自身研究结果,综述了强化Mg合金和Mg基复合材料的研究和开发,介绍了几种新型的强化Mg合金和Mg基复合材料.文献表明,材料性能与合金成分,晶粒大小,增强体的类型、形状、分布、体积分数,增强体与基体的界面,制备工艺等诸多因素有关. 相似文献
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《Materials Science & Technology》2013,29(10):1582-1587
AbstractIn the present investigation, the microstructural characterisation of the AZ91 Mg alloy produced by spark plasma sintering (SPS), as well as the evaluation of its hot compression behaviour, has been performed. Based on the differential scanning calorimetry analyses of the starting powders, three SPS cycles are investigated, using temperatures of 400 and 450°C, and at 450°C with previous solubilisation soaking at 420°C. Despite different microstructural and hardness characteristics, the three alloys display similar hot compression behaviour. At 200°C, the formation of an unstable crack, which propagates at 45° with respect to the loading axis, is observed after the occurrence of the peak load. At higher testing temperatures, after reaching the peak stress, the flow stress decreases slowly with increased strain of ~0·51. Such behaviour corresponds with the observation of an accelerated cracking due to the propagation of decohesions at the interparticle regions. Ultimately, SPS allowed for attainment of high relative density; however, the sintering degree of the materials was quite low. 相似文献