Microstructure‐Sensitive Model for Predicting Surface Residual Stress Relaxation and Redistribution in a P/M Nickel‐Base Superalloy

Burba, M. E.; Buchanan, Dennis J.; Caton, M. J.; John, Reji; Brockman, R. A.

doi:10.1002/9781119075646.ch66

Cited by 3 publications

(2 citation statements)

References 24 publications

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“…9,16,17 Comparatively, the two material orientations undergo linear hardening at room temperature; however, at 650 C, the longitudinal columnar-grained response exhibits the appearance of perfectly plastic or heterogeneous slip immediately after yielding, after which the material begins to gradually strain-harden under multi-slip conditions. Near-identical tensile behaviors have been reported for fine-grained Inconel 100 18 and single-crystal CMSX-2 19 in the intermediate temperature regime. Figure 9 shows the fracture surfaces of the columnar-grained material at room temperature and 650 C. Different fracture mechanisms can be observed between the two material orientations.…”

Section: Mechanical Behaviorsupporting

confidence: 69%

Strategy for Texture Management in Metals Additive Manufacturing

Kirka

Lee

Greeley

et al. 2017

JOM

137

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Additive manufacturing (AM) technologies have long been recognized for their ability to fabricate complex geometric components directly from models conceptualized through computers, allowing for complicated designs and assemblies to be fabricated at lower costs, with shorter time to market, and improved function. Lacking behind the design complexity aspect is the ability to fully exploit AM processes for control over texture within AM components. Currently, standard heat-fill strategies utilized in AM processes result in largely columnar grain structures. Proposed in this work is a point heat source fill for the electron beam melting (EBM) process through which the texture in AM materials can be controlled. Through this point heat source strategy, the ability to form either columnar or equiaxed grain structures upon solidification through changes in the process parameters associated with the point heat source fill is demonstrated for the nickel-base superalloy, Inconel 718. Mechanically, the material is demonstrated to exhibit either anisotropic properties for the columnar-grained material fabricated through using the standard raster scan of the EBM process or isotropic properties for the equiaxed material fabricated using the point heat source fill.

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Section: Mechanical Behaviorsupporting

confidence: 69%

Strategy for Texture Management in Metals Additive Manufacturing

Kirka

Lee

Greeley

et al. 2017

JOM

137

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“…The cutting force causes uneven plastic deformation of the surface layer of the workpiece. This is manifested in two ways: a "plastic protrusion" effect in the front area of the tool contact point; a "squeezing effect" caused by the tool flank [20]. The former causes residual tensile stress on the machined surface; the latter produces residual compressive stress.…”

Section: Discussionmentioning

confidence: 99%

An Investigation of the Influence of a Micro-Textured Ball End Cutter’s Different Parameters on the Surface Residual Stress of a Titanium Alloy Workpiece

Yang¹,

Shen²,

Liu³

et al. 2019

JMMP

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When machining titanium alloy parts, aside from accuracy, the other key concern when evaluating their quality is the integrity of the machined surface. Residual stress can have a significant impact upon this. A certain amount of residual stress can help to strengthen the workpiece, but excessive residual stress can lead to its deformation. In this paper, we report on an experimental study of the surface integrity of titanium alloy after milling with a microtextured ball-end cutter. Tests were conducted to assess the residual stresses on the surface of titanium alloy workpieces according to the direction of feed and milling. The impact of different micro-texture parameters was also assessed; namely, the diameter, depth, spacing and distance from the cutting edge of the individual pits. Range analysis, which is an orthogonal test, was used to analyze the results of the experiments and a prediction model of surface residual stress was established for the milling of titanium alloy with micro-textured ball-end cutters. This model can provide theoretical support for the optimization of the parameters involved in future milling processes.

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