Effects of ball burnishing on surface properties of low density polyethylene

We have end milled surfaces and then applied ball burnishing to specimens of low density high molecular mass polyethylene (LDPE). An important objective was roughness minimization. For selected ball diameters, the influence of burnishing parameters such as force F and burnishing speed f on selected surface geometry parameters has been determined: roughness Ra, total height of the profile Rt, and also the two-dimensional roughness change KRa. We find the minimum value of Ra=0.57 µm and the maximum value of KRa=5.1, both highly desired results. In the best case, Rt has decreased from 14.5 µm to 4.0 µm. Microhardness values, ball-on-disc wear values and scratch resistance testing all show property improvement of milled and burnished surfaces as compared to surfaces milled only. Burnishing decreases the wear rate by 58%.

We have applied end milling followed by ball burnishing to low density polyethylene. See the results for wear in the Figure:Figure optionsDownload high-quality image (77 K)Download as PowerPoint slide