SUMMARY

Laser assisted micro milling (LAMM) is a promising micro machining process for difficult-to-cut materials. LAMM uses a laser to thermally soften the workpiece prior to micro milling, thus lowering the cutting forces, improving the dimensional accuracy, and reducing tool wear. Thermal softening, however, causes the workpiece material to adhere to the tool and form a built up edge. To mitigate this problem and to enhance the micro machinability of the workpiece material, this thesis investigates the following two lubrication and cooling methods that have not been studied in prior work on LAMM: (i) minimum quantity lubrication (MQL), and (ii) vortex cooling. LAMM experiments using the two methods are carried out on a difficult-to-cut high content nickel-base alloy steel (A-286) and various aspects of micro machinability including tool condition, dimensional accuracy of the cut feature, surface finish, and cutting forces are analyzed. Possible physical reasons for the experimental observations are given.