Advanced Solid Phase Processing Symposium: Advanced Applications and Modeling
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Mechanical Behavior of Materials Committee, TMS: Shaping and Forming Committee
Program Organizers: Suveen Mathaudhu, Colorado School of Mines; Cynthia Powell, Pacific Northwest National Laboratory; Kester Clarke, Los Alamos National Laboratory; Anthony Reynolds, University of South Carolina; Mostafa Hassani, Cornell University
Tuesday 8:30 AM
February 25, 2020
Room: Balboa
Location: Marriott Marquis Hotel
Session Chair: Cynthia Powell, Pacific Northwest National Laboratory; Kester Clark, Colorado School of Mines
8:30 AM Invited
Impulse for Solid-State Processing: Glenn Daehn1; Anupam Vivek1; Brian Thurston1; Bhuvi Nirudhoddi1; 1Ohio State University
Brief and high pressure contact can be very useful for developing exceptional microstructures and useful component shapes. Here the means of developing very high pressures will be briefly reviewed, and we will focus on two: the vaporizing foil actuator method and laser-based impulse. Then several applications of impulse will be reviewed with a focus on two: impact welding and shock-based stress modification or relief. In the former case we will demonstrate that impact is a very versatile method for "welding the un-weldable" and that shocks can be used in a very versatile way to modify stress distributions and effectively eliminate springback to net shapes. A common them with both these applications is that they offer new routes to processes that are usually accomplished thermally. This opens new vistas.
8:55 AM Invited
Structure-property Relationships in Solid Phase Processing and Emerging Applications: Glenn Grant1; Scott Whalen1; Vineet Joshi1; Xiao Li1; Mageshwari Komarasami1; Jorge F. Dos Santos2; 1Pacific Northwest National Laboratory; 2Helmholtz-Zentrum Geesthacht GmbH; Pacific Northwest National Laboratory
Solid Phase Processing (SPP) involves the application of a high shear strain during metals synthesis or fabrication to produce high-performance microstructures in alloys, semi-finished products and engineered assemblies, without melting the constitutive materials. The family of SPP methodologies includes Friction Stir Welding and Processing, High Pressure Torsion, ECAP, Shear-assisted Extrusion (ShAPE), Friction Extrusion, MELD, Friction Surfacing, and other processing methodologies that induce intense levels of shear into deforming solids. The high levels of shear strain can take a material far from its equilibrium state to persistently metastable microstructures with unprecedented properties. This talk will illustrate some of the microstructures that have developed in different metallic systems processed through high-shear thermomechanical paths, and outline a few of the unique structural and thermophysical properties that have been observed. The talk will conclude with a discussion of emerging applications where SPP processed materials could make a dramatic impact on improved performance and function.
9:20 AM
Shear Assisted Solid Phase Processing of Aluminum Alloys: Keerti Kappagantula1; Jens Darsell1; Rajib Kalsar1; Nicole Overman1; Scott Whalen1; Glenn Grant1; Darrell Herling1; Vineet Joshi1; 1Pacific Northwest National Laboratory
Shear assisted processing and extrusion (ShAPE) is an emerging high-strain, solid-phase processing (SPP) technique; it can be used to manufacture metallic parts without melting the constituent materials. ShAPE can refine microstructures and develop preferred textures in a single step precluding the need for energy-intensive processing steps typically employed in conventional alloy development and part manufacturing. Parts manufactured using ShAPE process demonstrate unique property combinations that are challenging to achieve using traditional manufacturing routes. In this talk, the distinctive features of AA6061 and AA7075 rods processed using the ShAPE technique will be presented. Effect of the ShAPE process on precipitate formation and distribution and grain morphology will be discussed. The mechanical performance achieved with SPP methods will be compared and contrasted with those produced by conventional processing methods.
9:40 AM
A Computational Approach with Experimental Support to Study the Effect of Interfacial Characteristics on The Performance of Dissimilar Joints via Friction Stir Scribe Technique: Daniel Ramirez1; Panagiota Kitsopoulos2; Varun Gupta3; Piyush Upadhyay3; Tianhao Wang3; Erin Barker3; Darrell Herling3; 1University of Texas, San Antonio; 2Case Western Reserve University; 3Pacific Northwest National Laboratory
Friction stir scribe technique (FSST) is becoming a popular method to join dissimilar materials in lap configuration. The mechanical properties and performance of a FSST joint are governed by its underlying interfacial and microstructural characteristics, which in turn are determined by the process parameters. In this work, a finite element method based computational approach with experimental support was developed to identify the optimal interfacial characteristics that lead to desirable mechanical performance of a FSST joint. The accuracy of the computational model was verified by experimental observations. A sensitivity analysis was conducted to study the variation in the mechanical response and failure mode of the joint with respect to the interfacial characteristics. Results indicate that interfacial characteristics can have a significant impact on the joint strength and ductility.
10:00 AM Break
10:20 AM Invited
Shear-induced Diffusion and Intermixing: Atomic-level Perspective from Molecular Dynamics Simulations: Peter Sushko1; Brianna Collins2; Tiffany Kaspar1; Junhui Tao1; Bharat Gwalani1; Arun Devaraj1; Tamas Varga1; Yang He1; Chongmin Wang1; Aashish Rohatgi1; Cynthia Powell1; Suveen Mathaudhu3; 1Pacific Northwest National Laboratory; 2Pacific Northwest National Laboratory; University of Minnesota ; 3Pacific Northwest National Laboratory; University of California, Riverside
Materials processing approaches that bypass melting-solidification, such as high shear rate processing, offer an opportunity to generate a virtually unlimited variety of far-from-equilibrium phases with unique mechanical properties. In order to predictively explore this phase space, it is essential to reveal and learn to control mechanistic pathways of mass transfer, from single atom diffusion to collective effects, under non-equilibrium conditions. We generate atomistic insight into the mechanisms of mass transfer by performic molecular dynamics simulations for two types of immiscible systems. Comparison of the shear-induced dynamics in Cu/Cr heterostructures with an ideal and defect-containing interfaces allows us to identify precursor local structures that promote cross-interface intermixing and domain intergrowth. Simulations of Si particle reorientation in the Al host reveal an interplay of Al and Si diffusion processes at the particle/host interface, modulated by the local density fluctuations. These results are correlated with experimental observations of Cu/Cr and Al-Si shear-induced transformations.
10:45 AM
Dynamic Recrystallization Model Under Large Deformation During Solid Phase Processing: Yulan Li1; Shenyang Hu1; Erin Barker1; Suveen Mathaudhu2; 1Pacific Northwest National Laboratory; 2University of California-Riverside
Prediction of microstructure evolution during solid phase processing (SPP) is crucial for optimizing the operation parameters to achieve desired material microstructures and properties. The microstructure evolution during SPP refers to the temporal dislocation density and distribution, the nucleation of new grains and/or new phases. In this work, we present a dynamic recrystallization model under large deformation. The focuses are on the evolution of dislocation network structure and the nucleation of recrystallized grains. The fast Fourier transform (FFT)-based crystal plasticity model is employed to handle the large deformation in polycrystals. The associated plastic shear strain rate and resolved shear stress determine dislocation density and distribution which in turn determine the nucleation location and rate of recrystallized grains. Phase field method is used to model the recrystallized gain formation and grain structure evolution. Simulation results under typical stress state during Shear Assisted Processing Extrusion (ShAPE) will demonstrate the model capability.
11:05 AM
MD Simulations of Deformation Mechanisms and Sub-grain Formation in Al-Si Alloys Under High Shear Deformation: Shenyang Hu1; Suveen Mathaudhu2; Nanjun Chen1; 1Pacific Northwest National Laboratory; 2University of California, Riverside
Solid phase processing (SPP) methods such as Shear Assisted Processing and Extrusion (ShAPE) have been emerging a powerful material fabrication technique. Through SPP, alloys can be fabricated, that would be difficult-to-impossible to be produced via conventional processing methods due to chemical incompatibilities in the melt. Furthermore, unique microstructures and material properties in semi-fabricated products are not attainable through melt/solidification processing. During the SPP, high shear strains and elevated local temperature are induced which drive the material away-from equilibrium and result in the formation of metastable and/or unstable structures. The metastable structures ultimately affect the phase stability, microstructure evolution, and material properties. However, the mechanisms of deformation and metastable structure formation during SPP is not well understood. In this work, we employ molecular dynamics method to investigate the effect of initial microstructures and operation conditions on dislocation structure evolution and phase stability in polycrystalline Al-Si alloys under high shear deformation.