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Finding the input specifications to obtain the specified performance of a component being designed is an essential activity of a designer. However, obtaining solutions for this inverse problem is a complex task; especially when there are multiple steps with many-to-one mappings at each step in the forward problem. This complexity is further augmented in the presence of uncertainty of the parameters and models used. The typical heat treatment process involves multiple steps and the same outcome can possibly be achieved through multiple routes. Obtaining suitable process parameters for desired final properties such as the hardness profile is a requirement of the process design. In this work an error metric called the Hyper Dimensional Error Margin Index (HD_EMI) is used for inverse process chain design where the objective is to obtain the process set points in a sequence of heat treatment operations involving carburization, quenching and tempering processes. We have validated the solution of inverse problem by solving the detailed forward problem. The application procedure used in this study to solve inverse problem is simple and results obtained are encouraging for further exploration of HD_EMI.

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In order to leverage the concept of integrated computational materials engineering (ICME) for manufacturing of high-performance automotive transmission components such as steel gears, it is important to bring a closer collaboration between geometrical design, material selection, and manufacturing design stages for these components. This can be achieved by making the manufacturers aware of the implications of the decisions taken during each of these stages on material and its underlying microstructure. In order to facilitate this, it is necessary to model the evolution of the microstructure in the process-chain and its resultant properties. With this view, the current work focusses on development of an integrated modeling scheme of carburizing, quenching, and tempering processes using chemical composition-dependent, microstructure-based models intended to be used in an ICME framework for steel gear manufacturing. The individual process models are implemented in the commercial FEM suite ABAQUS™, with essential microstructure physics incorporated via user-subroutines. The individual process-models and their sequential integration are validated against experimental case-studies from literature. After validation, the integrated modeling scheme is automated by writing appropriate pre-processing and post-processing wrapper scripts, leading to the development of an independent manufacturing module that can be used in an ICME workflow. Finally, the utility of this module is demonstrated by using it for the exploration of the manufacturing process design and material selection scenarios for the production of a typical spur gear.

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