Accession Number : ADA321214

Title :   Microstructure-Driven Design.

Descriptive Note : Final rept.,

Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH MATERIALS DIRECTORATE

Personal Author(s) : Hughes, T. J. ; Muller, A.

PDF Url : ADA321214

Report Date : MAY 1996

Pagination or Media Count : 102

Abstract : Microstructure driven design, the application of optimal design and control methods to metal forming manufacturing processes can reduce part costs, improve part delivery schedules, and increase quality repeatability. Existing design methods are usually ad hoc and include inadequate evaluation of process parameters such as deformation rates, die and workpiece temperatures, and tooling system configuration. The systems approach used in this work is based on control theory and optimization concepts. A metal forming operation is viewed here as a combination of two interdependent systems: the microstructure development system and the process system. Inputs to the microstructure development system are field variables of the process, such as strain, strain rate, and deformation temperature. Microstructural system outputs are variables that characterize microstructure; in a dynamic recrystallization case, for example, grain size and volume fraction transformed are outputs of the microstructural system. The process system takes as inputs variables such as die profiles, preform shapes and temperature, and ram velocity profiles, and outputs field variables - strain, strain-rate and temperature - to which the different areas of the deforming workpiece are subjected during hot forming. Outputs of the process system are inputs to the microstructure development system. These presentations describe the microstructure development system and related issues as applied to process optimization.

Descriptors :   *MICROSTRUCTURE, *OPTIMIZATION, *SYSTEMS ENGINEERING, *METALWORKING, VELOCITY, OUTPUT, METHODOLOGY, TEMPERATURE, MANUFACTURING, DYNAMICS, DEFORMATION, RATES, GRAIN SIZE, DIES, STRAIN RATE, VARIABLES, COSTS, PROFILES, CONFIGURATIONS, OPERATION, SYSTEMS APPROACH, CONTROL THEORY, RECRYSTALLIZATION, HOT WORKING, TOOLING.

Subject Categories : Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE