Physical Simulation of Investment Casting of Complex Shape Parts
- PDF / 3,990,614 Bytes
- 11 Pages / 593.972 x 792 pts Page_size
- 96 Downloads / 187 Views
RODUCTION
INVESTMENT casting process, known as a lost wax casting or precision casting, is a well established process for production of near net-shape components. Due to excellent surface finish and dimensional accuracy, this process is especially useful for casting of complex shape containing thin sections.[1] This manufacturing technique has been widely used for fabrication of various parts (such as disks, stators, nozzle guide vanes (NGV), etc.) for aero-engines and gas turbines. As these parts are exploited at high temperatures and aggressive environments, they are typically made from high-density Ni-based superalloys showing high strength, excellent oxidation, and creep resistance at such service conditions.[2] The search for reduced weight and increased efficiency of aero-engines and gas turbines is driving changes in design of parts to more complex shapes and thinner geometries. However, these innovations are often hindered by the complexity of investment casting
MEHDI RAHIMIAN, Research Assistant, SRDJAN MILENKOVIC, Researcher, Head of Solidification Processing and Engineering Group, and ILCHAT SABIROV, Senior Researcher, Head of Physical Simulation Group, are with the IMDEA Materials Institute, Calle Eric Kandel 2, 28906 Getafe, Madrid, Spain. Contact e-mail: [email protected] LAURA MAESTRO, Simulation Engineer, and AITOR EGUIDAZU RUIZ DE AZUA, Process Engineer, are with the Precicast Bilbao, El Carmen s/n, 48901 Barakaldo, Spain. Manuscript submitted October 17, 2014. METALLURGICAL AND MATERIALS TRANSACTIONS A
of parts with thin elements. Development of investment casting routes for the complex shape parts is usually carried out via a ‘trial and error’ approach or, in other words, via experimental casting trials. The casting parameters are varied until good quality castings are produced. However, this strategy is very expensive and time consuming.[3] Modeling of investment casting is another approach to determine the optimum casting parameters.[4] Simulation of casting is reliable when the accurate data of materials are known at processing conditions, and boundary conditions are defined precisely. Casting simulation was applied by Gonzales et al.[5] to visualize mold filling and heat transfer during casting and solidification in order to predict microstructure and location of internal defects. The existing casting simulation tools are able to predict the local thermal profile, local grain structure, and defects (gas porosity, shrinkage pores, etc.) in the as-solidified complex shape parts.[6] However, precise prediction of local phase composition, second phase precipitates, segregations, etc., is out of capabilities of the current casting simulation tools, whereas these microstructural features significantly affect the local mechanical and functional properties in the castings from Ni-based superalloys. Physical simulation of metallurgical processes is often employed for development of novel manufacturing routes. Physical simulation involves the exact reproduction of the thermal and mechanical processes in t
Data Loading...
