Clarification of the sliding contact wear mechanism between thin coated magnetic disc and head

为了阐明薄涂层磁盘与磁头接触时的滑动接触磨损机理，对模拟模型与实际磁头涂层磁盘进行了实验和分析研究。1.模拟模型与实际磁头涂层磁盘的摩擦磨损试验。在60g~500g的小载荷下，对1 mm厚的Al基磁盘上溅射了铜、钛和二氧化硅三种涂层磁盘进行了销盘磨损试验。将封头建模为不锈钢销钉，测量了销钉在摩擦热作用下的摩擦系数和温度。实验结果表明，每种涂层材料的摩擦系数在0.2~0.6之间。结果表明，摩擦热的分布和传递与涂层和销钉材料的导热比成正比，摩擦系数可用…来估算。2.旋转滑动作用下涂层圆盘的机械应力和瞬时热应力分析利用摩擦系数和摩擦热的实验结果，对涂层圆盘中的机械应力和热应力进行了分析，并对其分布进行了数值计算。径向和周向热应力显示在接触载荷下母材拼接表面上的最大压应力，以及圆盘背面的最大拉应力。加载方向的机械应力表现为沿厚度均匀分布的最大压应力。3.表面裂纹应力强度因子和裂纹扩展的断裂力学分析作为一个实际的破坏实例，考虑了含有多个表面裂纹的涂层材料。从断裂力学的角度分析了应力强度因子，考虑了裂纹的扩展。结果表明，由于相互干涉，应力强度因子的大小随着裂纹间距的减小而减小，并且干涉效应与涂层材料无关。较少

In order to clarify the sliding contact wear mechanism of a thin coated magnetic disc being in contact with a head, following experimental and analytical research were carried out for the analogous model to the actual disc with a head.1.Friction and wear test of the analogous model to the actual coated disc with a headThe pin-on-disc wear test were carried out for three kind of coating discs spattering Cu,Ti and SiO_2 on the Al based disc with 1mm thick under small loading 60g〜500g. The head was modeled as a pin made of stainless steel, and the frictional coefficient and temperature of pin due to frictional heat were measured. As a result of this experiment, the value of frictional coefficient is obtained as 0.2〜0.6 for each coating materials. From the result of temperature, it is suggested that the frictional heat is distributed and transferred in proportion to the ratio of thermal conductivity of coating and pin materials, and the frictional coefficient can be estimated by the value … More of steady temperature.2.Analysis of mechanical stresses and transient thermal stresses of coating disc due to rotating slidingUsing the experimental results of frictional coefficient and frictional heat, mechanical and thermal stresses in coating disc are analyzed and their distributions are calculated numerically. The radial and circumferential thermal stresses show the maximum compressive stresses on the splicing surface of the base metal beneath the contact load and show the maximum tensile stresses on the back surface of the disc. The mechanical stresses of load direction show the maximum compressive stresses distributed uniformly over the thickness. The shearing stresses due to the frictional load show the maximum value at the both surface of the disc.3.Fracture mechanics analysis for stress intensity factors of the surface cracks and crack growthAs an actual failure example, the coating materials with multiple surface cracks are considered. The stress intensity factors are analyzed the crack growth are considered in the fracture mechanics viewpoint. It is shown that the magnitude of stress intensity factors decrease with a decrease of the distance between the cracks due to the mutual interference and the interference effect is independent of coating materials. Less