共查询到20条相似文献,搜索用时 140 毫秒
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利用钛与碳化硼及石墨之间的自蔓燃高温合成反应,经非自耗电弧熔炼工艺制备了TiB晶须和TiC粒子混杂增强的钛基复合材料。借助扫描电镜和透射电镜观察了复合材料的微观结构,结果表明:原位合成增强体均匀地分布在基体合金中,TiB增强体以晶须状生长,而TiC增强体以树枝状、等轴状生长。原位合成增强体与基体合金的界面非常干净,不存在界面反应产物,但TiC粒子周围的基体合金中存在高密度的位错。原位合成增强体的加入提高了复合材料的力学性能,合金化元素铝的加入不仅固溶强化了钛基体合金,同时使增强体长得更为细小,也有利于改善复合材料的性能。 相似文献
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原位生成TiBw/Ti复合材料的微观组织及高温压缩变形过程的演化规律 总被引:2,自引:0,他引:2
用粉末冶金原位合成法制备了TiB晶须增强钛基复台材料。利用扫描电镜和X射线衍射方法对经挤压变形后复合材料的微观结构进行了分析。在复合材料中观察到反应生成的TiB晶须。复合材料经过热挤压变形后,TiB晶须沿挤压方向定向排列。对挤压态TiBw/Ti复合材料进行高温压缩变形,TiB晶须在热压缩变形过程中发生转动或折断现象,变形温度越低,晶须折断现象越严重。 相似文献
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陶瓷质晶须及其在复合材料中的应用 总被引:6,自引:0,他引:6
具有优异力学性能和物理性能的晶须是发展现代非连续增强复合材料的新一代高性能增强剂,综述了陶瓷晶须的性能,生长机制,制备方法的研究,探讨了陶瓷质晶须在复合材料中应用,指出陶瓷质晶须及其在复合材料应用中存在的问题以及今后的研究方向。 相似文献
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《功能材料》2020,(7)
以Al-Al_2O_3-B_2O_3为反应体系,采用接触反应法制备了原位自生Al_(18)B_4O_(33)w/6061复合材料,利用XRD和SEM对复合材料分别进行物相分析及微观形貌观察,对比6061基体材料,研究了Al_(18)B_4O_(33)晶须对复合材料硬度和耐磨性能的影响。结果表明,采用接触反应法,利用Al-Al_2O_3-B_2O_3反应体系可直接在6061基体材料中原位自生针状Al_(18)B_4O_(33)晶须,Al_(18)B_4O_(33)晶须直径为0.1~2μm,晶须伴生于Mg元素。经T6热处理后,Al_(18)B_4O_(33)w/6061复合材料的硬度为HB 132.7,较6061基体提高了27.4%,硬度的提高机制为位错强化和细晶强化。Al_(18)B_4O_(33)w/6061复合材料的比磨损率和平均摩擦系数分别为1.96×10~(-8) kg/(N·m)和0.221,较6061基体下降了12.11%和22.46%。采用原位自生工艺制备的Al_(18)B_4O_(33)w/6061复合材料,晶须与基体材料之间的润湿性和界面结合强度良好,且晶须本身强度高,在磨损时能够起到支撑作用,减小了基体的应变和磨损,有效地提高了复合材料的耐磨性。 相似文献
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纳米 KTi6O13w合成中的形态演化和生长机理 总被引:1,自引:0,他引:1
以纳米TiO2为原料,通过煅烧反应制备了纳米K2Ti6O13晶须,对晶须合成中温度和时间诱导的相变、形态演化和生长机理等进行了原位研究.结果表明;纳米TiO2作原料可显著降低晶须合成温度,适宜的煅烧温度为900-1100℃.形态演化观察和高温XRD分析表明;K2Ti6O13晶须的相变及生长对温度极为敏感,形态演化是基于初期爆发式的相变和随后串并联式的长大.K2Ti6O13晶须的生长遵守本研究提出的串并联机制,晶须轴向的生长台阶是串并联生长的直接结果. 相似文献
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Theoretical analysis of a sandwich cement-based piezoelectric composite is presented based on the theory of piezo-elasticity. The steady-state responses of two kinds of this composite under different loading cases are obtained by the use of displacement method. The effects of piezoelectric phases on the performance of this kind of devices are simulated and discussed. The solutions are compared with both the numerical and experimental results, and good agreements are found. Sandwich cement-based piezoelectric composites have great application potential in civil structure health monitoring. The results obtained in this paper are beneficial to the design of this kind of smart devices. 相似文献
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介绍了电力蓄能技术在上海及周边地区的应用情况,并通过几个蓄能工程应用实例;阐述了电力蓄能综合节能技术的优势以及应用前景;根据目前电力蓄能应用存在的问题,呼吁从供电单位到应用单位的方方面面,共同努力,为缓解用电矛盾作贡献。 相似文献
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New parametric study of nugget size in resistance spot welding process using finite element method 总被引:2,自引:0,他引:2
Resistance spot welding process (RSW) is one of important manufacturing processes in automotive industry for assembling bodies. Quality and strength of the welds and therefore body mainly are defined by quality of the weld nuggets. The most effective parameters in this process are: current intensity, welding time, sheet thickness and material, geometry of electrodes, electrode force, and current shunting. In present research, a mechanical–electrical–thermal coupled model in a finite element analysis environment is made using. Via simulating this process, the phenomenon of nugget formation and the effects of process parameters on this phenomenon are studied. Moreover, the effects of welding parameters on temperature of faying surface are studied. Using this analysis, shape and size of weld nuggets are computed and validated by comparing them with experimental results from published articles. The methodology developed in this paper provides prediction of quality and shape of the weld nuggets with variation of each process parameter. Utilizing this methodology assists in adjusting welding parameters so that costly experimental works can be avoided. In addition, the process can be economically optimized to manufacture quality automotive bodies. 相似文献