Dominant Factors in Lubricant Transfer and Accumulation in Slider-Disk Interface

Abstract

Lubricant transfer from disk to slider and lubricant accumulation on slider are very important in designing a stable slider-disk interface of ultra-low spacing. In this article, the effects of different parameters on the lubricant transfer and accumulation are studied and the reasons behind the effects are explained. Furthermore, the time for the lubricant transfer to reach steady state is estimated. It is found that lubricant molecular weight plays a dominant role in the lubricant transfer and accumulation. Lubricant transfer and accumulation decrease dramatically with the increase in lubricant molecular weight. Lubricant transfer also strongly depends on lubricant thickness and bonding ratio on disk surface. A thinner lubricant and higher lubricant bonding ratio on disk surface reduce lubricant transfer obviously, which results in less lubricant accumulation. A diamond-like-carbon (DLC) overcoat of low adsorption area density on slider surface can reduce lubricant transfer and accumulation, especially for lubricant of low molecular weight. Lubricant accumulation increases with disk velocity and increases slightly with the decrease in slider flying height. Lubricant accumulation can be reduced by minimizing the area of slider pad. Lubricant transfer and accumulation become worse at higher ambient temperature. It takes seconds for lubricant of low molecular weight to reach steady transferred thickness and hours for lubricant of high molecular weight to reach the steady state.

Effect of surface topography of disk on lubricant distribution and lubricant transfer between disk and slider

“…学者们对磁头/磁盘之间润滑剂转移的数值研究 结果表明: 增加润滑剂分子的重量 [4] , 增加润滑剂的 吸附率 [5] , 提高润滑剂分子链的刚度 [6] 或减小润滑膜 的厚度 [5] 都可以减少磁头/磁盘之间的润滑剂转移. Man 等人 [7] 的研究结果表明磁头的空气轴承表面设 计会对磁头/磁盘之间的润滑剂转移产生影响.…”

Effects of SiO2 Contaminant on Thermo-Mechanical/Chemical Properties and Lubricity of PFPE Lubricants

“…They claimed that the presence of these contaminants and foreign particles inside HDDs can accelerate the lubricant transfer process. For these reasons, researchers have investigated the contamination of the air-bearing-surface (ABS) of a head slider through experiments and numerical simulations [8][9][10][11][12][13][14]. Various approaches were proposed to describe the mechanisms on how lubricants are transferred and picked up to a head surface, which includes the process of material evaporation, desorption, condensation, and molecular interaction in the HDI.…”

Adsorbed Water Film and Heat Conduction from Disk to Slider in Heat-Assisted Magnetic Recording

“…Lubricant transfer in slider-disk interface and accumulation on slider cause severe problems to head-disk interface. It has been proven that even without sliderlubricant contact, lubricant still can be transferred from disk to slider via evaporation and condensation [15,16]. Recently, the effects of humidity on the lubricant transfer were studied experimentally [17].…”