April L. Cooke, Eric Whitenton, Jarred Heigel, and Robert Ivester

Manufacturing Metrology Division, MEL, NIST Gaithersburg, MD 20899.



The use of titanium alloys in industrial and commercial applications is increasing due to attractive properties such as high strength-to-weight ratio, corrosion resistance, and low thermal conductivity. However, many of the characteristics that make titanium alloys popular are the same characteristics that severely complicate its machining operations. The scope of this study is to investigate one of the complications that arise while machining titanium, the formation of adiabatic shear bands. The physical mechanisms that cause this phenomenon are not well understood, but the presence of these shear bands can have negative effects on the surface integrity of finished parts, decrease the life of the cutting tools, and cause machine tool vibrations during the manufacturing process. In this work, a high-speed camera was used to acquire videos of dynamic chip formation at a microscopic level during orthogonal cutting operations on Ti-6Al-4V, the most common titanium alloy used in industry. The chips formed during the cutting tests were saved, analyzed with scanning electron microscopy, and the results, along with the acquired videos and finite element modeling of the cutting operation, were examined. The knowledge gained in this research provides insight that will be used to assess and decrease the uncertainty of physics-based machining models that industry uses to improve machining processes.





CATEGORY: Engineering



Mentorís Name: Robert Ivester

Division, Laboratory: Manufacturing Metrology, MEL

Room, Building, Mail stop: A149/233, MS 8220

Tel: (301) 975-3850

Fax: (301) 975-8058



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