Abstract:
Nanofinished aluminum alloys are widely used in optics as metallic mirrors, micro-electronics and micro-mechanical
assemblies. In general, the ductile materials like aluminum and copper are being machined by diamond
turn machining (DTM) process to get the nanometric surface finish. However, it is impossible to achieve an
atomic level surface finish by conventional random finishing processes like lapping. With a newly developed
chemo mechanical magnetorheological finishing (CMMRF) process, an experimental investigation has been
carried out on Al-alloy by implementing suitable chemical reactions on the superficial layer of the workpiece. A
full experimental design has been performed to optimize the process by varying several parameters such as
concentration of chemicals, concentration of abrasives, concentration of carbonyl iron particles and working
gap. Effect of different parameters has been studied an average surface roughness value (Ra) of less than 2 nm
was achieved, which was further improved by optimizing the process parameters. The best result of CMMRF
finished aluminum (0.597 nm) was way better than DTM and chemo-mechanical polishing process. In terms of
reflectance, in the range of 300–2200 nm the processed surface was found to have 5% higher value in comparison
with sputtered counterpart. Also, it was observed that finishing of aluminum caused its surface to shift
from hydrophilic to hydrophobic and then to the super-hydrophilic region with a contact angle of 16°. By this
experimentation, more than 98% improvement on surface finish has been observed. Therefore, it has been
concluded that the CMMRF process can finish aluminum alloy of the order of few angstrom.
