Effects of Humid Air on Air-Bearing Flying Height

• Published in: IEEE transactions on magnetics Vol. 43; no. 7; pp. 3301 - 3304
• Main Authors: Strom, B.D., Shuyu Zhang, Sung Chang Lee, Khurshudov, A., Tyndall, G.W.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Air bearing; Air bearings; Condensing; Corrosion; Cross-disciplinary physics: materials science; rheology; Disk recording; Exact sciences and technology; Flight; Flying; flying height; Gas bearings; hard disk drive; Hard disks; Humidity measurement; humidy; Information systems; Magnetic levitation; Magnetic recording; Magnetism; Materials science; Moisture; Other topics in materials science; Physics; Saturation; Temperature dependence; Temperature distribution; Vapor pressure; Water vapor; Air bearing; Hard discs; Disc drives; humidy; flying height; hard disk drive; Air; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2007.897085

The pressure distribution in a squeeze film air bearing depends on the water vapor pressure and the saturation vapor pressure of water at ambient temperature. When the water vapor pressure is compressed beyond the saturation vapor pressure, a portion of the water vapor condenses, thus reducing the total gas pressure in the air bearing. This condensation mechanism thus reduces the flying height of the slider. Using a magnetic recording system for experiments, we quantified the effect of condensation on flying height by measuring the dependence of magnetic spacing on relative humidity. We developed a numerical model based on the proposed mechanism that matches the experimental data and provides a detailed view of the air-bearing response to humidity.