Justin D. Morrow

Predicting laser polishing outcomes at edge features

The field of laser polishing has grown to include many strategies and materials, but several barriers remain to widespread commercialization of this technology, one being a lack of predictive capability of how laser polishing affects part edge features. The objective of the present work is to present a method of predicting this change in edge geometry and compare the results with experimental observation of laser polishing on blunt, square, and sharp edges. This was done by measuring the edge geometry before and after polishing using optical focus-variation metrology and comparing this with a prediction from a laser polishing simulation. The results showed good agreement in the edge rounding behavior between simulation and experiment except for an asymmetry of the observed polished edge at higher power that is not captured in the capillary smoothing model. This indicates that the present model can act as a good model for predicting edge rounding at lower power conditions, but additional capability in predicting material buildup and displacement at higher power needs to be added for fully predictive capability.The field of laser polishing has grown to include many strategies and materials, but several barriers remain to widespread commercialization of this technology, one being a lack of predictive capability of how laser polishing affects part edge features. The objective of the present work is to present a method of predicting this change in edge geometry and compare the results with experimental observation of laser polishing on blunt, square, and sharp edges. This was done by measuring the edge geometry before and after polishing using optical focus-variation metrology and comparing this with a prediction from a laser polishing simulation. The results showed good agreement in the edge rounding behavior between simulation and experiment except for an asymmetry of the observed polished edge at higher power that is not captured in the capillary smoothing model. This indicates that the present model can act as a good model...

Synthesis and Characterization of ZrO2 Coatings on Micro End Mills With Sol–Gel Processing

The objective of this paper is to develop a coating method for placing ultrathin zirconia films, fabricated using sol–gel methods, onto micro end mills. Sol–gel synthesis is investigated because of its potential as a low energy and inexpensive method for depositing a variety of wear resistant and chemically stable oxide coatings that could potentially extend tool life. Two sol–gel based deposition methods are investigated: dip-coating and electrophoretic deposition (EPD). The coatings are deposited on 300-μm-diameter micro end mills. Initial results suggest that sol–gel coating methods can produce the required coverage and conformity in the cutting zone. However, preliminary findings show that the coating is removed in the cutting zone after a short time of machining (6 s). The tool pretreatment and extent of sintering, which affect surface adhesion coating mechanical properties, require further study and optimization.