Micromilling of metal alloys with focused ion beam–fabricated tools

• Published in: Precision engineering Vol. 25; no. 2; pp. 107 - 113
• Main Authors: Adams, David P., Vasile, Michael J., Benavides, Gilbert, Campbell, Ann N.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.04.2001; Elsevier Science
• Subjects: Applied sciences; Blanking. Shearing; Brass; Cutting; Cutting tools; Exact sciences and technology; Metals. Metallurgy; Micromachining; Micromilling; Microtools; Milling (machining); Polymethyl methacrylates; Production techniques; Steel; Surface roughness; Ultra-precision machining; Micromilling; Ultra-precision machining; Microtools; Tungsten carbide; Milling cutter; Brass; Precision engineering; High precision; Roughness; Machining; Ion beam; Methyl methacrylate polymer; Mechanical clearance; Focused ion beam technology; Sputtering; Sputter coating; Cutting; Carbide tool; Penetration rate; High speed tool steel; Ion beam sputtering; Micromachining; Rupture; Machine feed; Aluminium alloy; Rough surface; Milling; Cutting tool; Curvature
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/S0141-6359(00)00064-7

This work combines focused ion beam sputtering and ultra-precision machining as a first step in fabricating metal alloy microcomponents. Micro-end mills having ∼25 μm diameters are made by sputtering cobalt M42 high-speed steel and C2 micrograin tungsten carbide tool blanks. A 20 keV focused gallium ion beam is used to define a number of cutting edges and tool end clearance. Cutting edge radii of curvature are less than or equal to 0.1 μm. Micro-end mill tools having 2, 4 and 5 cutting edges successfully machine millimeter long trenches in 6061-T4 aluminum, brass, 4340 steel and polymethyl methacrylate. Machined trench widths are approximately equal to the tool diameters, and surface roughnesses (R a) at the bottom of micromachined features are ∼200 nm. Microtools are robust and operate for more than 6 h without fracture. Results from ultra-precision machining aluminum alloy at feed rates as high as 50 mm/minute and an axial depth of 1.0 μm are included.