Browsing by Author "Paiva, Jose Mario"

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    Benchmarking of several material constitutive models for tribology, wear, and other mechanical deformation simulations of Ti6Al4V
    (Elsevier, 2019-05-12) Liu, Cen; Goel, Saurav; Llavori, Iñigo; Stolf, Pietro; Giusca, Claudiu L.; Zabala, Alaitz; Kohlscheen, Joern; Paiva, Jose Mario; Endrino, José L.; Veldhuis, Stephen C.; Fox-Rabinovich, German S.
    Use of an alpha-beta (multiphase HCP-BCC) titanium alloy, Ti6Al4V, is ubiquitous in a wide range of engineering applications. The previous decade of finite element analysis research on various titanium alloys for numerous biomedical applications especially in the field of orthopedics has led to the development of more than half a dozen material constitutive models, with no comparison available between them. Part of this problem stems from the complexity of developing a vectorised user-defined material subroutine (VUMAT) and the different conditions (strain rate, temperature and composition of material) in which these models are experimentally informed. This paper examines the extant literature to review these models and provides quantitative benchmarking against the tabulated material model and a power law model of Ti6Al4V taking the test case of a uniaxial tensile and cutting simulation.
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    The role of high-pressure coolant in the wear characteristics of WC-Co tools during the cutting of Ti-6Al-4V
    (Elsevier, 2019-10-12) Stolf, Pietro; Paiva, Jose Mario; Ahmed, Yassmin Seid; Endrino, José L.; Goel, Saurav; Veldhuis, Stephen C.
    Aeronautic applications have been making use of titanium alloys for decades. Ti–6Al–4V is one of the most commonly applied alloys, and although its mechanical properties warrant its acceptance for many applications, the machinability of this alloy remains a challenge. So far, the most successful technique in facilitating this alloy's machining has been the application of High-Pressure Coolant Supply (HPC) on account of its influence on the tribological aspects of the cutting operation. On that premise, this work employs experimental and computational resources to advance the current understanding of the wear mechanism in terms of the tool-chip contact conditions and establish a correlation between coolant pressure, cutting speed, tool life, cutting forces, and chip formation when machining Ti–6Al–4V with HPC supply. Results showed that HPC plays a role in the reduction of tool-chip temperature profiles and contact stresses, positively impacting tool flank wear, oxidation levels and chip formation, also improving chip breakability.