A new quasi-nano wear mechanism (QNWM) has been proposed in this paper based on the facts of wear curve turning under high energy impact contact loading.Its characteristic is that the wear rate of QNWM is only 1/10-1/...A new quasi-nano wear mechanism (QNWM) has been proposed in this paper based on the facts of wear curve turning under high energy impact contact loading.Its characteristic is that the wear rate of QNWM is only 1/10-1/3 that of delamination mechanism at the same energy density.The diameters of wear debris and pits on the worn surfaces fall into the quasi-nanometer scale (about 50-120 nm).The necessary and sufficient conditions,which bring about the QNWM,are:(i) the nano-structure (nano-crystalline + amorphous phase) in impact contact surface layer has formed by the intensive impact strain;(ii) the delamination wear cracking in sub-surface layer must be restrained;(iii) the microcracks of QNWM are produced in amorphous phase of surface nano-structure layer rather than in nano-crystalline.展开更多
纳米材料独特的表面性质可以使材料改性,从而生产出性能优越、满足不同需要的油田化学添加剂。以十六烷基三甲基氯化铵(CTAC)为主要原料,研究了纳米ZnO通过拟交联作用,对CTAC蠕虫状胶束黏度、耐温和降滤失性能的影响,分析了其作用机理...纳米材料独特的表面性质可以使材料改性,从而生产出性能优越、满足不同需要的油田化学添加剂。以十六烷基三甲基氯化铵(CTAC)为主要原料,研究了纳米ZnO通过拟交联作用,对CTAC蠕虫状胶束黏度、耐温和降滤失性能的影响,分析了其作用机理。研究结果表明,水杨酸钠与CTAC的物质的量比为1.25∶1时,体系形成最大长度的蠕虫状胶束,黏度达到最大;纳米ZnO能够改善CTAC黏弹性胶束溶液的黏度、热稳定性和剪切稳定性,尤其在中低温增黏效果显著,90℃高温时仍有增黏作用,改性体系黏度可以保持在60 m Pa·s;优化得出纳米ZnO的质量分数为0.2%时对体系增黏效果最好;具有极高比表面积的纳米ZnO很容易吸附在胶束表面,屏蔽了胶束之间的静电排斥作用,使CTAC胶束形成一种更加稳定的三维网状结构;改性体系符合Maxwell流体模型,是具有单一松弛时间的线性黏弹性流体。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.50071045,50471036)
文摘A new quasi-nano wear mechanism (QNWM) has been proposed in this paper based on the facts of wear curve turning under high energy impact contact loading.Its characteristic is that the wear rate of QNWM is only 1/10-1/3 that of delamination mechanism at the same energy density.The diameters of wear debris and pits on the worn surfaces fall into the quasi-nanometer scale (about 50-120 nm).The necessary and sufficient conditions,which bring about the QNWM,are:(i) the nano-structure (nano-crystalline + amorphous phase) in impact contact surface layer has formed by the intensive impact strain;(ii) the delamination wear cracking in sub-surface layer must be restrained;(iii) the microcracks of QNWM are produced in amorphous phase of surface nano-structure layer rather than in nano-crystalline.
文摘纳米材料独特的表面性质可以使材料改性,从而生产出性能优越、满足不同需要的油田化学添加剂。以十六烷基三甲基氯化铵(CTAC)为主要原料,研究了纳米ZnO通过拟交联作用,对CTAC蠕虫状胶束黏度、耐温和降滤失性能的影响,分析了其作用机理。研究结果表明,水杨酸钠与CTAC的物质的量比为1.25∶1时,体系形成最大长度的蠕虫状胶束,黏度达到最大;纳米ZnO能够改善CTAC黏弹性胶束溶液的黏度、热稳定性和剪切稳定性,尤其在中低温增黏效果显著,90℃高温时仍有增黏作用,改性体系黏度可以保持在60 m Pa·s;优化得出纳米ZnO的质量分数为0.2%时对体系增黏效果最好;具有极高比表面积的纳米ZnO很容易吸附在胶束表面,屏蔽了胶束之间的静电排斥作用,使CTAC胶束形成一种更加稳定的三维网状结构;改性体系符合Maxwell流体模型,是具有单一松弛时间的线性黏弹性流体。
