SBIR Phase II: Monte Carlo Simulation - A Design Tool for Investment Casting

拟议的SBIR第二阶段项目将完成软件设计工具的开发，该工具将用于预测先进材料加工中的金属和合金的晶格结构。该软件将是一个非常重要的工具，具有广泛的商业和技术价值。颗粒结构是影响材料性能的主要因素，在几乎所有材料加工应用中都必须仔细考虑。先进计算能力的出现使得在工程设计中使用计算机模拟成为可能。一期工程结果表明，利用高端台式计算机模拟铸件凝固组织是可行的。采用带工艺控制参数的蒙特卡罗模拟(MCS)方法，成功地模拟了高温合金熔模铸件中典型的细晶铸件的晶核和长大过程。结果表明，热流可以直接纳入到模型中，MCS可以用来模拟铸态组织的大部分重要特征。拟议的第11阶段研究的目标将是开发一个稳健的模型，用于模拟凝固过程中的铸晶组织、形核和生长。为实现这一目标，计划开展六项研究工作。在第一个任务中，将定义MCS过程控制参数的物理组件。在第二项任务中，将为这些组件中的每一个构建一个数值模型，并对MCS计算机代码进行数学格式化。在第三个任务中，将从文献中获得这些数值模型的热物理常数。在第四项任务中，将评估使用有限差分法和有限元方法模拟热流的相对优点。在第五个任务中，将通过与典型铸件的晶粒组织实验数据的比较来验证模拟结果。最后，在第六个任务中，将为MCS模型开发一个原型软件包。原型软件将为第三阶段的研究成果商业化奠定基础。该软件的成功商业化将使美国工业在先进材料加工领域更具生产力和竞争力。先进材料加工行业的代表豪迈公司将继续参与这一项目。模拟先进材料加工，提高熔模铸件的质量，控制材料加工过程中的颗粒组织，为先进材料加工提供新的应用软件，设计和开发材料加工。

DMI-9531304 Jaske The proposed SBIR Phase II project will complete the development of a software design tool that will be used to predict the grain structure of metals and alloys in advanced materials processing. This software will be a very important tool with broad commercial and technical value. Grain structure is a primary factor in materials properties and must be carefully considered in almost all materials processing applications. The advent of easy access to advanced computing power has made it possible to use computer simulation in engineering design. Results of the Phase I project showed that it is feasible to simulate the solidification grain structure of cast materials using high-end desktop computers. Monte Carlo Simulation (MCS) with a process control parameter was successfully employed to model grain nucleation and growth in fine-grain castings that are typical of superalloy investment castings. It was found that heat flow can be incorporated directly into the model and that MCS can be used to model most of the important features of cast grain structures. The objective of the proposed Phase 11 research will be to develop a robust model for simulation of cast grain structure nucleation and growth during solidification. Six research tasks are planned to achieve this objective. In the first task, the physical components of the MCS process control parameter will defined. A numerical model for each of these components will be constructed and mathematically formatted for the MCS computer code in the second task. In the third task, thermophysical constants for these numerical models will be obtained from the literature. The relative merits of using finite-difference versus finite-element methods to model heat flow will be evaluated in the fourth task. In the fifth task, the simulation results will be validated by means of comparisons with experimental data on grain structures for representative castings. Finally, a prototype software package for the MCS model will be developed in the sixth task. The prototype software will provide the base for commercializing the research results in Phase III. Successful commercialization of the software will make US industry more productive and competitive in the area of advanced materials processing. A representative of the advanced materials processing industry, Howmet Corporation, will continue participating in this project. Modeling Advanced Materials Processing, Improving the Quality of Investment Castings, Controlling Grain Structure during Materials Processing, Providing New Software for Application to the Processing of Advanced Materials, Designing and Developing Materials Processing.