Thermo-Mechanical Processing Parameters for the INCONEL ALLOY 740

In 2000, a Cooperative Research and Development Agreement (CRADA) was undertaken between the Oak Ridge National Laboratory (ORNL) and the Special Metals Corporation (SMC) to determine the mechanical property response of the IN740 alloy to help establish thermo-mechanical processing parameters for the use of this alloy in supercritical and ultra-critical boiler tubes with the potential for other end uses. SMC had developed an alloy, commercially known as INCONEL alloy 740, which exhibited various beneficial physical, mechanical, and chemical properties. As part of SMC's on-going efforts to optimize this alloy for targeted boiler applications there was a need to develop an understanding of the thermo-mechanical response of the material, characterize the resulting microstructure from this processing, and possibly, utilize models to develop the appropriate processing scheme for this product

Predictive Model and Methodology for Heat Treatment Distortion

The purpose of this project was to develop a modeling methodology and software tool to simulate and predict the results of heat treatment, especially distortion. In order to develop a simulation tool, significant technical, analytical, and experimental resources were needed. This task was too large and complex for just one company or organization to address. To this end, 4 national laboratories (Los Alamos National Laboratory, Lawrence Livermore National Laboratory, the Oak Ridge National Laboratory/Y-12 Plant, and Sandia National Laboratories) and many partners working through NCMS tackled this effort. The participants through NCMS were Ford Motor Company, General Motors Corporation, The Torrington Company, Deformation Control Technologies, The MacNeal-Schwindler Corp. IIT Research Institute, the Gear Research Institute, U.S. Benet Laboratories (Army), and the Colorado School of Mines. For the purpose of this report only those items pertinent to the Oak Ridge National Laboratory/Y-12 Plant participation in this CRADA will be highlighted along with those related items directly related to these specific efforts that were accomplished by the partners

Use of High Magnetic Field to Control Microstructural Evolution in Metallic and Magnetic Materials

The Amendment 1, referred to as Phase 2, to the original CRADA NFE-06-00414 added tasks 3 through 7 to the original statement of work that had two main tasks that were successfully accomplished in Phase 1 of this project. In this Phase 2 CRADA extension, extensive research and development activities were conducted using high magnetic field processing effects for the purpose of manipulating microstructure in the SAE 5160 steel to refine grain size isothermally and to develop nanocrystalline spacing pearlite during continuous cooling, and to enhance the formability/forgability of the non-ferrous precipitation hardening magnesium alloy AZ90 by applying a high magnetic field during deformation processing to investigate potential magnetoplasticity in this material. Significant experimental issues (especially non-isothermal conditions evolving upon insertion of an isothermal sample in the high magnetic field) were encountered in the isothermal phase transformation reversal experiments (Task 4) that later were determined to be due to various condensed matter physics phenomenon such as the magnetocaloric (MCE) effect that occurs in the vicinity of a materials Curie temperature. Similarly the experimental deformation rig had components for monitoring deformation/strain (Task 3) that were susceptible to the high magnetic field of the ORNL Thermomagnetic Processing facility 9-T superconducting magnet that caused electronic components to fail or record erroneous (very noisy) signals. Limited experiments on developing nanocrystalline spacing pearlite were not sufficient to elucidate the impact of high magnetic field processing on the final pearlite spacing since significant statistical evaluation of many pearlite colonies would need to be done to be conclusive. Since extensive effort was devoted to resolving issues for Tasks 3 and 7, only results for these focused activities are included in this final CRADA report along with those for Task 7 (described in the Objectives Section of this report)

Rapid tooling for functional prototyping of metal mold processes. CRADA final report

The overall scope of this endeavor was to develop an integrated computer system, running on a network of heterogeneous computers, that would allow the rapid development of tool designs, and then use process models to determine whether the initial tooling would have characteristics which produce the prototype parts. The major thrust of this program for ORNL was the definition of the requirements for the development of the integrated die design system with the functional purpose to link part design, tool design, and component fabrication through a seamless software environment. The principal product would be a system control program that would coordinate the various application programs and implement the data transfer so that any networked workstation would be useable. The overall system control architecture was to be required to easily facilitate any changes, upgrades, or replacements of the model from either the manufacturing end or the design criteria standpoint. The initial design of such a program is described in the section labeled ``Control Program Design``. A critical aspect of this research was the design of the system flow chart showing the exact system components and the data to be transferred. All of the major system components would have been configured to ensure data file compatibility and transferability across the Internet. The intent was to use commercially available packages to model the various manufacturing processes for creating the die and die inserts in addition to modeling the processes for which these parts were to be used. In order to meet all of these requirements, investigative research was conducted to determine the system flow features and software components within the various organizations contributing to this project. This research is summarized

Intelligent decision support technologies for design and manufacturing

For many of today`s complex manufacturing processes, there exists a solid body of knowledge that enables direct simulations of such processes yielding predictions about the final product and process characteristics using finite element or finite difference methods. However, the computational complexities of these simulations are such that they do not lend themselves easily to routine and timely use in optimization and control of manufacturing processes. More recently, neural network-based decision support technologies have been developed which hold the promise of bringing the body of analytical and simulation knowledge closer to the design and optimization processes in manufacturing industries. The paper discusses the application of a holistic approach wherein existing finite element, neural-network, and optical metrology methods are combined to develop a real time tool for optimization and control of the sheet metal stamping process. Significant issues in the development of such a tool and results from its application to a deformation process are discussed

Magnetic Processing – A Pervasive Energy Efficient Technology for Next Generation Materials for Aerospace and Specialty Steel Markets

Thermomagnetic Magnetic Processing is an exceptionally fertile, pervasive and cross-cutting technology that is just now being recognized by several major industry leaders for its significant potential to increase energy efficiency and materials performance for a myriad of energy intensive industries in a variety of areas and applications. ORNL has pioneered the use and development of large magnetic fields in thermomagnetically processing (T-MP) materials for altering materials phase equilibria and transformation kinetics. ORNL has discovered that using magnetic fields, we can produce unique materials responses. T-MP can produce unique phase stabilities & microstructures with improved materials performance for structural and functional applications not achieved with traditional processing techniques. These results suggest that there are unprecedented opportunities to produce significantly enhanced materials properties via atomistic level (nano-) microstructural control and manipulation. ORNL (in addition to others) have shown that grain boundary chemistry and precipitation kinetics are also affected by large magnetic fields. This CRADA has taken advantage of ORNL’s unique, custom-designed thermo-magnetic, 9 Tesla superconducting magnet facility that enables rapid heating and cooling of metallic components within the magnet bore; as well as ORNL’s expertise in high magnetic field (HMF) research. Carpenter Technologies, Corp., is a a US-based industrial company, that provides enhanced performance alloys for the Aerospace and Specialty Steel products. In this CRADA, Carpenter Technologies, Corp., is focusing on applying ORNL’s Thermomagnetic Magnetic Processing (TMP) technology to improve their current and future proprietary materials’ product performance and open up new markets for their Aerospace and Specialty Steel products. Unprecedented mechanical property performance improvements have been demonstrated for a high strength bainitic alloy industrial/commercial alloy that is envisioned to provide the potential for new markets for this alloy. These thermomechanical processing results provide these alloys with a major breakthrough demonstrating that simultaneous improvements in yield strength and ductility are achieved: 12 %, 10%, 13%, and 22% increases in yield strength, elongation, reduction-in-area, and impact energy respectively. In addition, TMP appears to overcome detrimental chemical homogeneity impacts on uniform microstructure evolution

Toughness-strength relations in the overaged 7449 Al-Based alloy

This article examines the relationship between plane strain fracture toughness, KIc, the tensile properties, and the microstructure of the overaged 7449 aluminum-plate alloy, and compares them to the 7150 alloy. The 7449 alloy has a higher content of ??/? precipitates; and, the 7150 alloy contains a greater amount of coarse intermetallic particles, as it contains an appreciable amount of coarse S phase (Al2CuMg), which is largely absent in the 7449 alloy. The toughness of the alloys shows an increase on overaging, and the 7449 alloy shows a reasonably linear toughness—yield strength relation on extended overaging. Several mechanisms of failure occur: coarse voiding at intermetallics and a combined intergranular/transgranular shear fracture mode, with the former becoming more important as overaging progresses. Drawbacks of existing models for toughness are discussed, and a new model for plane strain fracture toughness, based on the microstructurally dependent work-hardening factor, KA, introduced in Ashby's theory of work hardening, is developed. This model predicts a linear relation between KIc and K0.85A/?0.35ys, where ?ys is the yield strength, which is consistent with the experimental data