Bringing AFS Research into Focus.
AFS' greatest strength also is its greatest obstacle: its diverse membership has diverse needs. AFS is composed of metalcasters, metalcasting suppliers and individual members, and it provides unique programming for individual audiences addressing metal-specific, process-specific and organizational functional business responsibilities.
A strategic plan was developed during a series of meetings in the early 1990s to identify and address future requirements through precompetitive research. In these meetings, leaders of several metalcasting and supplier organizations identified seven fundamental technical and business needs, including:
* products and markets--New cast metal processes required to exceed the technical demands of new product designs and material specifications are needed;
* materials technology--Quality, availability, cost and properties of engineered alloys, casting media and tooling materials are required to meet market demands through environmentally responsible manufacturing;
* manufacturing technology--Continued progress in developing advanced design and manufacturing technologies is needed to improve the timelines, productivity and efficiency of delivering consistent, highquality engineered structures in the international marketplace;
* environmental technology--Existing infrastructure realities and technical capabilities must be considered to establish long-range global environmental strategies with realistic timetables;
* human resources--Continuous education of the metalcasting workforce and its management is needed to take full advantage of the information revolution. Equally important is outreaching to manufacturing engineers who must be familiar with current and accurate information on the capabilities and potential of metalcasting;
* profitability and industry health--Retaining skilled human resources, attracting new talent, investing in new technical capabilities and diversifying markets are needed to manage the newly emerging global business climate;
* partnerships--Innovative business systems must be created through partnerships among educational institutions, national laboratories, suppliers, metalcasters and original equipment manufacturers.
Transforming Thought into Action
There are 50 active research projects valued over $13 million that are supported by the 13 AFS divisions. Projects can be funded by inkind committee support or AFS research funds. AFS division-approved requests for project funds are forwarded quarterly to the Research Board. AFS partners with the American Metalcasting Consortium (AMC), Cast Metals Coalition (CMC), Solidification Design and Control Consortium, and the U.S. Council on Automotive Research and Design and Product Optimization (USCAR-DPO) to externally fund AFS projects.
USCAR and the Transportation Technology Office of the Dept. of Energy (DOE-TT) team with AFS to improve light metals design for product optimization (DPO) for expanding automotive markets. This project is designed to address barriers for the high-volume application of high-strength cast structural aluminum and magnesium components for use in chassis and body components to reduce vehicle mass. Lack of comprehensive material design guidelines, limited supplier base for automotive production rates, and improved casting quality and consistency are customer concerns.
The joint effort of three national laboratories (Oak Ridge National laboratory, Lawrence Livermore National Laboratory and Sandia National Laboratory) with the Georgia Institute of Technology is developing component evaluation methodology to predict mechanical properties of a casting as a function of the local microstructure. Another task is developing online nondestructive evaluation techniques to ensure casting consistency and quality. This 5-year effort will be completed in April 2000, and a summary report will be made available to all AFS members with a comprehensive CD-ROM technical data package distributed to the sponsors.
Individual programs can provide a milestone breakthrough, however an equally important strategy is to design complementary programs to meet larger needs. Three thrusts discussed in this article include:
* providing reliable preliminary design property data;
* applying information technology to expand market share. The application of solidification software, cupola melting software, electronic transfer of digital files and electronic commerce offers metalcasting an innovative environment to serve established and new markets;
* developing the technical base for zero-discharge manufacturing. Today, more than 95% of metal is recycled within the industry. Recycling or reusing molding particulate is the next big challenge.
Thrust I-Preliminary Design Property Data
Two of the several programs that address the technical objective of developing representative industry mechanical property data are the AFS-funded "Critical Assessment of Cast Iron Fatigue Properties" and the CMC-funded "Design Parameters for Permanent Mold Cast Copper-Based Engineering Alloys." The long-term goal is to collect mechanical property data for all cast metals with the corresponding microstructural characterization information into a single searchable database that is representative of the industry capability.
To optimize component geometry and mass, modern design methods rely on axial strain-life fatigue data to predict finite component life. Most published cast iron fatigue data consists of rotating beam tests or fatigue limit tests. Strain-controlled fatigue properties are available to automotive design engineers for wrought steel and aluminum alloys in the Society of Automotive Engineers specification "Technical Report on Fatigue Properties" but not for casting alloys.
Mechanical, corrosion and wear properties as well as static and dynamic mechanical properties such as fracture toughness, impact toughness and fatigue properties required by the engineering design community for six permanent mold cast copper-base engineering alloys are being developed. These include aluminum bronzes (C95200 and C95400), high-manganese yellow brasses (C99700 and C99750) and high-copper alloys (C8l500 and C8250). The slurry wear resistance of permanent mold cast alloys C95400, C95500 and C86300 was determined in two different test configurations and compared with sand mold castings. The corrosion behaviors of these alloys also were evaluated. All mechanical properties were strongly dependent on the chemical composition. Alloys exhibiting relatively high tensile ductility often exhibited high fracture and impact toughness. The nominal composition does not always provide the best combination of strength and ductility. To achieve optimum properties for a given application, a narrower composition range must be targeted, especially for those elements that have the greatest effect on properties.
Thrust II--Improve Quality and Expand Market Share with Information Technology
Several projects are funded by AFS and AMC, all aimed at teaching engineering students, design engineers, buyers and managers that metalcasting is among the most economical means to produce complex shapes. The complex nature of the metalcasting process has been one of the major beneficiaries of the information age, opening up opportunities through process modeling, rapid prototyping and concurrent engineering.
Current mechanical engineering curriculums do not provide adequate training on metalcasting, and engineering faculties do not possess accurate information to train new design engineers. Therefore, an interactive case study allows working design professionals to learn by example how to properly design and procure complex shapes.
Presently, many foundries use an internal code classification to characterize casting anomalies. There is a need for an organized system of collecting information on the process parameters relating to the potential anomalies. Also, there is a need for developing a database on the solution to the defects. Internal and external failures contribute to over 70% of the total quality costs in foundries. Quality costs in a foundry can vary between 3-15% of total sales while scrap and repair costs in U.S. foundries are more than $50 million annually. The "Quality Improvement system" website (www.4ebasic.com) will assist foundries in using a standard classification for casting anomalies to help identify directly related process parameters.
Thrust III--Zero Discharge Manufacturing
The third thrust includes projects that proactively and creatively address environmentally responsible manufacturing on several levels, The approach is to adapt the best available technology while developing innovative processes and materials technology.
The Environmental Protection Agency (EPA) is required by law to develop maximum achievable control technology (MACT) standards this year. Methods of reducing hazardous air pollutants from melting, pouring, cooling and shakeout must be based on accurate reliable scientific data. The AFS MACT task force is working with the EPA to ensure that the final MACT standards meet the requirements of the Clean Air Act without placing an unnecessary burden on the metalcasting industry. MACT is one of six projects that address zero discharge manufacturing.
The future health of the metalcasting industry is dependent upon the clarity of the vision of the future we have today. This vision allows AFS to work more effectively toward that objective by applying its volunteer committee members' talent and leveraging its partner support. The Research Board is responsible for developing with the AFS Division Council a vision for the future. The individual committees are responsible for shaping and implementing that vision through the identification, development and execution of projects addressing technical and business issues. AFS staff will work with the Board of Directors to develop the financial resources required to execute the necessary programs.
AMC's Research and Development Benefits Casting Use
The American Metalcasting Consortium (AMC) is composed of the Defense Logistics Agency (DLA), AFS, the Non-Ferrous Founders' Society (NFFS), the North American Die Casting Assn. (NADCA), and the Steel Founders' Society of America (SFSA). AMC's society partners represent a variety of large and small foundries. They are working together under the management of the Advanced Technology Institute to reduce cost, cut lead times and improve the quality of engineered cast metal components. In 1998, AMC teamed with the DLA to recommend design revisions for 40 components and convert six parts to castings, resulting in a $2.2-million cost reduction.
Below are a couple of the research and development projects prioritized by the industry and its customers that AMC is implementing to further drive down cost and time and increase quality.
"Fast Free Form Fabrication," Northwestern Univ.--The objective of this project is to benchmark and characterize the advantages and concerns of "Fast Free Form Fabrication" technologies as a critical enabling technology for the rapid production of first-article parts. Part geometry and complexity are important factors in determining appropriate and timely tooling methods that are being monitored together with part-specific cost, lead time and dimensional capability data. The preliminary knowledge base being created by this research will assist government and civilian procurement authorities in selecting suitable tooling for short-production, sand-cast parts.
"Casting Reject Reduction," Univ. of Alabama-Birmingham--Casting rejects discovered during machining force foundries to produce extra castings to satisfy orders. When substantial numbers of parts are rejected, especially during machining, deliveries are delayed, machining time and costs are lost, and the product cost and lead time is increased. This project is developing and testing practical concepts to improve metal handling and pouring to reduce both foundry and machine shop scrap. Traditional rigging practices are being compared to new concepts using commercial casting simulation software, and the predictions are verified using controlled experiments.
A second task addresses the issue of castings being rejected because of arbitrary inspection standards that have no engineering basis. Steel casting studies are focused on quantitatively assessing the effects of internal variations in properties on part performance.
SDC Conducts Earthbound Experiments
Individual companies have interacted in the past with the Auburn Univ. Solidification Design Consortium to address the metalcasting technical needs to maintain the U.S. leadership in quality, price and delivery.
AFS recently formed the Solidification Design and Control Consortium (SDCC) with the National Aeronautics and Space Administration Marshall Space Flight Center and Auburn Univ. This program utilizes the advantages of extended periods of microgravity and vacuum available in the International Space Station to empirically address solidification phenomena that cannot be definitively answered with ground-based studies. Last year, the following four projects were funded.
Virtual & Physical Simulation--The combination of virtual and physical simulation provides a powerful tool for understanding and validating fluid flow and solidification during metalcasting of alloys such as cast iron, aluminum, and nickel-base superalloys. Experiments are proposed to develop gating systems for casting complex shapes, which have quality issues associated with dross formation and gravity-driven turbulence.
Hot Tearing Light Metal Alloys--Improving the hot tear resistance of alloy 201 will reduce scrap and improve casting yield, and better mechanical properties can be expected at both ambient and elevated temperatures. With improved mechanical properties at elevated temperatures, aluminum alloy 201 is a good candidate for automotive applications such as exhaust manifolds.
Development of Computational Fluid Dynamics Software to Support Optimization of Sand Coreblowing Operations--This project will develop a multiphase software tool for sand core design and for optimizing the coreblowing process. This software tool can help make dimensionally consistent sand cores, reduce scrap, cut design lead times, optimize the coreblowing machine parameters, lessen resin requirements and tooling wear, and enable fully integrated modeling of sand core castings.
Microgravity Experiments for Enhancing the Development of Ferrous Castings--This project will explain a number of differences in the microstructure of microgravity cast near-eutectic iron carbon alloys compared to Earth gravity. Flotation of graphite was eliminated, dendrite arm spacing was increased, metastable eutectic interlamellar spacing was decreased and eutectic grain size was coarsened. These phenomena control the homogeneity of the microstructure, composition and properties of ferrous castings. Improvements would allow the use of ferrous castings in components currently restricted to wrought ferrous alloys and fabricated assemblies.
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|Author:||Santner, Joseph S.|
|Date:||Feb 1, 2000|
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