This Small Business Technology Transfer Research (STTR) Phase II project seeks to develop analytical techniques for finite element simulations of the warm hydroforming of aluminum, magnesium and other metals. This project will develop and test fixtures and instrumentation. The project objectives will be to develop methods and a system for simulating parts and validating designs prior to prototyping and to develop advanced research warm hydroforming tooling with optical measurement capabilities to validate the simulation and modeling method. Warm hydroforming is of interest because many metals have improved forming properties at moderately elevated temperatures, 450 °C or less. Warm hydroforming differs from superplastic forming with a focus on conventional alloys and short forming times. Warm hydroforming also requires lower forces and pressures so the cost of heating can be offset by reduced mechanical system requirements.
The broader impact/commercial potential from this technology will be the ability for manufacturers to use lighter, more fuel efficient materials without sacrificing strength, (automotive and aerospace industries) or to obtain shapes not possible at room temperature. The value proposition offered by warm hydroforming is: lighter weight materials can be formed with similar strength characteristics, allowing for more efficient and environmentally friendly vehicles and aircraft; greater deformations can be achieved without tearing or fracturing reducing the need for machining or joining operations; allows the creation of many features, such as mounting points or reinforcing ribs, in a single step; eliminate process steps no longer needed with warm hydroforming since parts are formed in one operation; and lower up front capital costs as the force required to form materials at elevated temperatures is much lower than at room temperature and this translates into significantly smaller, less expensive presses and related equipment. While automotive warm hydroforming applications have had high visibility, many other industries such as heating and air conditioning, recreational vehicles and building products where aluminum components are used could benefit from this technology and by introducing this technology into those industries may make them more competitive and efficient.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Parts manufactured from aluminum and magnesium are important components in many products. The weight reduction and corrosion resistance achieved with these materials improves products by increasing the ease of use, reducing energy consumption and enhancing durability. The formability of many aluminum and magnesium alloys is greatly improved with increased temperature. The range of temperatures is typically 200 to 400 °C. The goal is to predict the forming characteristics of sheet and tube at these temperatures. Hydroforming of parts for sheet or tube raw materials is of importance since it offers the opportunity to create multiple features in a single step. Also, joining operations can be eliminated and sources of leaks are reduced, In modern manufacturing practice the usual approach is simulating the forming processes to evaluate feasibility and develop the process plan prior to starting the prototype activity. This requires material parameters relevant to the forming processes. Bulge tests of sheet or tube samples impose stains and deformations similar to forming processes. Our development is a system of fixtures for performing these tests, optical instrumentation for measuring the strains and deformations and software for extracting material properties that can be used in finite element simulations. The products from this development will complement our Servo Press product line which is widely used by material suppliers and parts producers for formability evaluation. Specifically we now have heated fixtures for bulge testing sheet or tube materials at elevated temperatures. These fixtures will accommodate the use of optical measuring systems to measure strains and deformations. Also our control software can incorporate the data from the optical system. We have additional software to process the data and extract parameters suitable for use in finite element modeling of forming processes.
