title: An investigation of force components in orthogonal cutting of medical grade cobalt-chromium alloy (ASTM F1537).
abstract: An ageing population, increased physical activity and obesity are identified as lifestyle changes that are contributing to the ongoing growth in the use of in-vivo prosthetics for total hip and knee arthroplasty. Cobalt-chromium-molybdenum (Co-Cr-Mo) alloys, due to their mechanical properties and excellent biocompatibility, qualify as a class of materials that meet the stringent functional requirements of these devices. To cost effectively assure the required dimensional and geometric tolerances, manufacturers rely on high-precision machining. However, a comprehensive literature review has shown that there has been limited research into the fundamental mechanisms in mechanical cutting of these alloys. This article reports on the determination of the basic cutting-force coefficients in orthogonal cutting of medical grade Co-Cr-Mo alloy ASTM F1537 over an extended range of cutting speeds ([Formula: see text]) and levels of undeformed chip thickness ([Formula: see text]). A detailed characterisation of the segmented chip morphology over this range is also reported, allowing for an estimation of the shear plane angle and, overall, providing a basis for macro-mechanic modelling of more complex cutting processes. The results are compared with a baseline medical grade titanium alloy, Ti-6Al-4V ASTM F136, and it is shown that the tangential and thrust-force components generated were, respectively, ≈35% and ≈84% higher, depending primarily on undeformed chip thickness but with some influence of the cutting speed.
authors.affiliation: School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Baron
authors.affiliation: School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland.
authors.forename: Eamonn
authors.initials: E
authors.lastname: Ahearne
mesh_terms: D002858:Chromium Alloys; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods*; D055595:Mechanical Phenomena; D013499:Surface Properties
chemical_list: D002858:Chromium Alloys
keywords: Cobalt–chromium alloys; forces in cutting; orthogonal cutting