Time Resolved Friction During Sliding of Metal on Metal at Near Melt Interfacial Temperatures

9908189 Prakash将进行极端载荷和滑动速度条件下的摩擦研究。 这与许多技术上重要的情况有关，例如在超高速加工过程中的工具-工件界面，摩擦和爆炸焊接过程，枪管中加速壳的旋转带，高速冲击过程中的物体界面，轨道上的火箭驱动车辆以及汽车和飞机中使用的高性能制动衬片。 这些条件使得界面处的温度接近摩擦副中较低熔点材料的熔融状态。最近的发展，在实验方法来研究高速摩擦，使测量在这一地区，在施加的正常压力范围从3至5 GPa和滑移速度超过150米/秒。 拟议的研究将涉及，（i）高冲击速度的压力剪切板，对相对低熔点的金属，如铝的冲击摩擦实验，（ii）详细的瞬态有限变形弹粘塑性有限元模拟的冲击摩擦过程，以了解连续水平的预测程度的弹塑性相互作用的摩擦对材料，和（iii）详细的光学，电子显微镜、X射线衍射和荧光（EDS）研究，以了解滑动过程中的摩擦机械和摩擦化学相互作用。*

9908189PrakashA study of friction under extreme conditions of load and sliding velocity will be undertaken. This is relevant to a number of technologically important situations, such as at tool-workpiece interfaces during ultra-high speed machining, friction and explosive welding processes, rotating band of an accelerating shell in a gun barrel, interfaces of bodies during high velocity impact, rocket driven vehicles on rails, and high performance brake liners employed in automobiles and aircrafts. The conditions are such that the temperature at the interface approaches the melt regime of the lower melting point material in the tribo-pair. Recent developments in experimental methods to investigate high speed friction have enabled measurement in this region, at applied normal pressures ranging from 3 to 5 GPa and slip speeds of over 150 m/s. The proposed study will involve, (i) high impact velocity pressure-shear plate-impact friction experiments on relatively low melting point metals such as aluminum, (ii) detailed transient finite deformation elastic-visco-plastic finite element modeling of the impact friction process-in order to understand the continuum level predictions of the extent of elastic-plastic interactions of the tribo-pair materials, and (iii) detailed optical, electron microscopy, X-ray diffraction and flourescence (EDS) studies to understand the tribo-mechanical and tribo-chemical interactions during the sliding process.***