Copper - nanosized tibi composites were prepared by in - situ process . the microstructure , mechanical and electrical properties , and dry sliding wear behavior and electric sliding wear of cu - nanosized tib _ 2 in - situ composites was investigated ; mostly task as follows : the thermodynamic data for the reactions between b and ti in the molten liquid of copper were analyzed , the copper matrix composites reinforced by in - situ tibi nanoparticles were prepared by reactions of 8263 , carbon and titanium in copper - titanium melt , and copper - titanium , copper - boron in alloy melt , respectively , which controlled the reaction temperature , reaction time and solidification process . the rnicrostructure and mechanical and electrical properties of the in - situ composites were investigated by using optics microscope , tem and xrd 本文采用原位反应法制备了cu -纳米tib _ 2原位复合材料,在此基础上分析了原位复合材料的微结构,进行了干滑动摩擦磨损和电接触滑动磨损实验,完成的主要工作如下:从热力学的角度出发,分析了陶瓷tib _ 2颗粒在铜基体中原位生成的热力学条件,并用电解铜、工业纯钛、 b _ 2o _ 3 、 c (还原剂)以及cu - ti 、 cu - b等合金为原料,通过控制适当的反应温度、反应时间和快速凝固等工艺手段,制备了cu -纳米tib2原位复合材料。
It costs more than the traditional way and it is hard to control the process of the reaction . these disadvantages have led to some limitations of the composites " production and research . therefore , the developing orientation of in situ composites is to search the means of lowering the cost and controlli ng the process of in situ reaction 但外加法存在着诸如颗粒偏聚、润湿性差、界面强度结合低等缺点,而内生法由于增强颗粒是在基体内部原位反应生成,因此能克服外加法的缺点,但同时内生法所制备的金属基复合材料的成本太高、原位反应不易控制等缺点制约了复合材料的扩大应用,因此发展性能优异复合材料的出路在于寻找降低成本以及控制原位反应的措施。
The experimental results show that in situ reaction between several oxides and al balances adiabatic temperature and controls the drastic reaction between cuo and al . at the same time , this kind of in situ reaction also accelerates the other replacement reactions and makes them react till to the end 实验结果表明采用多种氧化物原位反应法合理调配了不同反应的绝热温度,控制了cuo与al剧烈的铝热反应,同时促进了其它单质氧化物与al反应,使其能自我维持进行下去。
But during the process of in situ reaction , in addition to the reinforced phase , composite will exit the other by - product ( such as fragility phase alsti and al4c3 ) , mean while , it is difficult to control the volume fraction of tic particles accurately , and lead to poor stability of material property 但是目前在原位反应时,除了所预计生成的增强体外,仍会生成其它副反应夹杂物(即脆性相al _ 3ti和al _ 4c _ 3的生成) ,同时对增强体tic颗粒的体积分数也难以精确控制,因而影响材料质量的稳定性。
反应: neaction定位反应: placing reaction方位反应: position reaction光定位反应: light compass reaction亏氢位反应: unsaturated-site reactions配位反应: complexation reaction; complexing reacion; complexing reaction; coordination reaction配位反应性: ligand reactivity直立位反应: orthostatic response皮肤电位反应: skin potential response相位反应曲线: phase response curve; phase-response curve用药部位反应: application site reaction植入部位反应: implant site reaction注射部位反应: injection site reaction电位反应听力检查: auditory evoked-response testing水位反应性系数: water-level reactivity coefficient药物植入部位反应: drug implant site reaction原位聚合酶链反应,原位pcr: in situ polymerase china reaction原位多聚酶链反应: in situ polymerase chain reaction原位: home position; i itu; in situ; insitu; normal position; root position原位聚合酶链式反应: in situ pcr听觉脑干诱发电位反应试验: auditory brainstem evoked potential response testkleijn静位反射: static reflex of magnus and de kleijn单位反馈: unit feedback定位反馈: feedback, position; position feedback定位反射: orientating reflex