Micro-pattern imprinting onto aluminum thin sheet by CNC-controlled stamping

Table-top CNC stamping system was developed to make fine precise forming onto thin work-sheet. Micro-embossing process was employed to investigate the imprinting behavior during precise stamping for various film thicknesses. A micro-patterned die was prepared by chemical etching and oxygen-plasma etching method. The protective DLC coating of tool steels was directly etched to have fine embossing pattern. This micro-patterned die unit was inserted into a cassette mold-die for stamping test. Aluminium sheets with the purity of 99.9 % and the thickness of 80 μm were employed as a thin film work-sheet in order to describe the imprinting behavior. Scanning electron microscope, laser microscope and laser profilometers were utilized to characterize the imprinted geometry onto these film sheets. Micro-grooving pattern was successfully imprinted onto DLC coating by oxygen plasma etching for various grooving widths from 3 to 100 μm and grooving pitches from 7 μm to 200 μm. Aluminium sheet with the aligned, square-wedged patterns was succesfully fabricated, asiming at the heat-radiation device.