Fabrication of Metal Micro-pin Array for Mechanical Interlocking on Rough Surface

Abstract

In this research, fabrication of metal micro-pin array for mechanical interlocking on rough surface was carried out. Nanosecond pulsed laser beam machining which has advantages for large area machining was applied and the machining methods that appropriate to the machining property of metals were proposed. In the case of stainless steel that has high viscosity and surface tension of its liquid state and that generates much dross and recast layer in laser beam machining process, dross and recast layer were piled for fabricating high aspect ratio micro-pin array. In the case of tungsten that is disadvantageous to precise machining using laser beam machining due to high melting point and high thermal conductivity, laser beam machining and electrochemical etching were used for fabricating micro-pin array. And the machining characteristics for each process were investigated according to machining parameters. Fabricated micro-pin array was applied for interlocking on rough surface. The interlocking force was measured according to micro-pin shape and rough surface conditions. The principle of micro-pin array interlocking on rough surface was investigated. Calculated force using interlocking model was compared with measured force. And interlocking force was estimated using surface profile and developed interlocking model. To increase applicability of micro-pin array interlocking, tilted micro-pin array and flexible base micro-pin array were developed. Tilted micro-pin array could generate more and directional interlocking force. Flexible base micro-pin array could interlock on curved rough surface