Magnetic Peripherals Inc.

Seagate Technology Incorporated

Amarjit S Brar

Jagdish P Sharma

Prativadi B Narayan

Suryanarayana Kaja

Jimmie E Mims

Anthony C Dierich

Jagdish P Sherma

A process for forming a bearing surface on an aluminum alloy article including the steps peening the surface, anodizing the surface, and washing the anodized surface with a boehmite inhibiting agent.

Process for forming a bearing surface for aluminum alloy

A magnesium alloy structural member for supporting at least one actuator arm in a hard disk drive and a method for making a shaped magnesium part having a fluorocarbon coating is disclosed. The coating is applied by exposing the member to a reactive gas in the presence of a glow discharge plasma to prevent corrosion. The glow discharge is generated by providing a vacuum environment at a pressure of between 250 and 300 millitorr in a reaction chamber and applying power to a pair of electrodes contained within the reaction chamber. Power is supplied at between about 100 and about 200 watts at about 13.6 megahertz, forming a low temperature glow discharge plasma. A reactive gas comprising a fluorinated alkane is introduced to the reaction chamber, and a pressure of between about 100 and about 300 millitorr is maintained. The structural member is exposed to the reactive gas and the plasma for an amount of time sufficient to form a thin and uniform polymeric fluorocarbon coating on the surface of the part. After the coating is formed, the chamber is purged with a hydrocarbon gas to consume any fluorine free radicals.

Fluorocarbon coated magnesium alloy carriage and method of coating a

An etching and fluorinating treatment is disclosed for modifying the surface properties of magnetic data storage media and sliders for magnetic data transducing heads. Media enclosed within a plasma chamber is first exposed to an argon plasma for cleaning, then exposed to a plasma mixture including argon with either fluorine or carbon tetrafluoride, maintained at a pressure of approximately half of atmospheric pressure, at a temperature of about 100.degree. C. An electrical field is generated for forming argon, carbon and fluorine ions. The argon ions etch the carbon overcoat of the disc, while the carbon and fluorine ions combine with the carbon to form extended chain fluoropolymers, and also penetrate the carbon layer. Sliders are treated in a plasma mixture of argon and CF.sub.4. During such treatment, carbon and fluorine ions penetrate exposed surface areas of the slider, and form a reaction product of solid lubricant film. In connection with both processes, ion penetration and reaction product formation reduce surface energy and strengthen cohesive bonding. The formation of a solid lubricant of extended chain fluoropolymers improves lubricity.

Plasma treatment for ceramic materials

Ceramic head pad materials which exhibit superior toughness and lubricating material characteristics over known materials, particularly in the areas of toughness resilience, damping, solid lubricity, reduced brittleness and chipping (without a change in bulk hardness), and improved thermal expansion, result from optimizing the amount of strontium oxide (SrO) and included in a calcium titanate ceramic. In particular, a ceramic material with approximately 5% to 7% SrO in a calcium titanate matrix (with approximately 6% SrO being the optimal concentration), may be utilized to realize the aforestated improved toughness and lubricating characteristics.

Improved ceramic head pad materials

A process for treating the surface of a die-cast article including the steps of chemically cleaning the surface, cleaning the surface with an argon plasma, depositing an ion vapor generated metallic coating, mechanically treating the deposited coating, and chromate converting the mechanically treated coating. Preferably, the die-cast metal article consists essentially of an aluminum or magnesium alloy while the metallic coating is aluminum. The mechanical treatment may be carried out by bead blasting, tumbling or barreling and may be followed by walnut shell polishing.

Micro-contamination-free coating for die-cast component in magnetic disk

A method for determining the micro impact energy capacity of a disk drive's ceramic heads and its thin film disks. The impact energy capacity of disk drive heads (typically composed of ceramic materials) and disks (higher capacity disks use thin film media) provides a measure of quality and durability of the heads and media. The method includes dropping an indentor of a known weight on a sample surface, measuring the identation surface area and length, increasing the weight and repeating the previous steps at different areas o the surface until surface cracking occurs. The various measurements are plotted to produce a stress-strain curve, the area of which comprises the micro energy capacity of the surface.

Method for determining the micro impact energy capacity of the surface

A ceramic head pad material which exhibits superior toughness and lubricating material characteristics over known materials, particularly in the areas of toughness/resilience, damping, solid lubricity, reduced brittleness and chipping (without a change in bulk hardness), and improved thermal expansion, results from optimizing the amount of strontium oxide (SrO) in a calcium titanate ceramic. In particular, a ceramic material with approximately 5% to 7% SrO in a calcium titanate matrix (with approximately 6% SrO being the optimal concentration), may be utilized to realize the aforestated improved toughness and lubricating characteristics.

High impact strength ceramic composite head pad material

Surface treatment for sliders and carbon coated magnetic media

An apparatus for testing the surface properties of a material is disclosed. The apparatus includes an indentor which is suspended above the surface of a sample and dropped onto the sample. Several testing methods are also disclosed. Surface toughness is measured by dropping the indentor from a variable height and inspecting the surface for failure. Thin film strength is tested by making several drops from various heights and inspecting the surface for flaking of the layer. In addition, damping capacity can be measured by comparing the kinetic energy of the resulting from the drop of the indentor to the strain energy measured by a probe on the opposing surface of the sample.

Apparatus and methods for testing surface properties of a material

A process for fabricating magnetic transducing heads includes successive grinding, lapping and finishing steps. The ferrite cores of the transducing heads are rough cut with a silicone carbide grinding wheel, to an excess over desired final throat height equal to approximately one-half the nominal diameter of the grinding wheel grit. The core and supporting pads then are placed on a soft tin or lead rotating lapping plate for removing substantially all of the excess. Finally, the pads and cores are hand-finished on a stationary plate or soft tin, copper or lead. A diamond slurry used during lapping and final finishing, has a controlled alkaline pH in order to simultaneously chemically etch and polish the cores.

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Edina, MN, United States of America

Amarjit S Brar