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Title: A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper

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Journal Article: Publisher's Accepted Manuscript
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Journal of Materials Processing Technology
Additional Journal Information:
Journal Volume: 216; Journal Issue: C; Related Information: CHORUS Timestamp: 2016-09-04 18:49:20; Journal ID: ISSN 0924-0136
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Liu, R., Salahshoor, M., Melkote, S. N., and Marusich, T.. A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper. Switzerland: N. p., 2015. Web. doi:10.1016/j.jmatprotec.2014.09.021.
Liu, R., Salahshoor, M., Melkote, S. N., & Marusich, T.. A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper. Switzerland. doi:10.1016/j.jmatprotec.2014.09.021.
Liu, R., Salahshoor, M., Melkote, S. N., and Marusich, T.. 2015. "A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper". Switzerland. doi:10.1016/j.jmatprotec.2014.09.021.
title = {A unified material model including dislocation drag and its application to simulation of orthogonal cutting of OFHC Copper},
author = {Liu, R. and Salahshoor, M. and Melkote, S. N. and Marusich, T.},
abstractNote = {},
doi = {10.1016/j.jmatprotec.2014.09.021},
journal = {Journal of Materials Processing Technology},
number = C,
volume = 216,
place = {Switzerland},
year = 2015,
month = 2

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Publisher's Version of Record at 10.1016/j.jmatprotec.2014.09.021

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Cited by: 16works
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  • Titanium alloys are materials considered as extremely difficult to cut and titanium alloy Ti6Al4V is a reference in machining of titanium. The segmented (saw toothed) chip morphology has attracted great interest in researchers because the understanding of the saw-toothed chip morphology helps to understand the chip formation mechanisms. In this study, the effect of different constitutive models on the saw-toothed chip morphology is examined in machining Ti6Al4V. The paper presents the influence of eight material constitutive modelling in the simulation of segmented chip formation. A critical comparison of outstanding process outputs as cutting force, temperature and measurable parameters for segmentedmore » chips is carried out to compare and discuss the performance of the eight different material models to each other and with experimental data.« less
  • The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial ormore » biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.« less
  • Clusters of self-interstitial atoms are formed in metals by high-energy displacement cascades, often in the form of small dislocation loops with a perfect Burgers vector. In isolation, they are able to undergo fast, thermally activated glide in the direction of their Burgers vector, but do not move in response to a uniform stress field. The present work considers their ability to glide under the influence of the stress of a gliding dislocation. If loops can be dragged by a dislocation, it would have consequences for the effective cross-section for dislocation interaction with other defects near its glide plane. The latticemore » resistance to loop drag cannot be simulated accurately by the elasticity theory of dislocations, so here it is investigated in iron and copper by atomic-scale computer simulation. It is shown that a row of loops lying within a few nanometres of the dislocation slip plane can be dragged at very high speed. The drag coefficient associated with this process has been determined as a function of metal, temperature and loop size and spacing. A model for loop drag, based on the diffusivity of interstitial loops, is presented. It is tested against data obtained for the effects of drag on the stress to move a dislocation and the conditions under which a dislocation breaks away from a row of loops.« less
  • The results of an experimental study of the contact heat conductance across a single diamond crystal interface with OFHC copper (Cu) are reported. Gallium-indium (GaIn) eutectic was used as an interstitial material. Contact conductance data are important in the design and the prediction of the performance of x-ray optics under high-heat-load conditions. Two sets of experiments were carried out. In one, the copper surface in contact with diamond was polished and then electroless plated with 1 {mu}m of nickel, while in the other, the copper contact surface was left as machined. The measured average interface heat conductances are 44.7{plus_minus}8 W/cm{supmore » 2}-K for nonplated copper and 23.0{plus_minus}8 W/cm{sup 2}-K for nickel-plated copper. For reference, the thermal contact conductances at a copper-copper interface (without diamond) were also measured, and the results are reported. A typical diamond monochromator, 0.2 mm thick, will absorb about 44 W under a standard undulator beam at the Advanced Photon Source. The measured conductance for nickel-plated copper suggests that the temperature drop across the interface of diamond and nickel-plated copper, with a 20 mm {sup 2}contact area, will be about 10{degree}C. Therefore temperature rises are rather modest, and the accuracy of the measured contact conductances presented here are sufficient for design purposes. {copyright} {ital 1996 American Institute of Physics.}« less
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