There is considerable industrial interest in the development of Hot Isostatic Pressing (HIP) of material powders into a truly net or near-net shape. The objective of this research is to set the basis for the development of an efficient methodology to predict shape changes in HIP. The study will characterize the two principal causes of shape distortion: (1) the effect of powder container stiffness, and (2) the formation of densification fronts by inhomogeneous heating. Iron powder will be used as a first target material for its mechanical behavior is well understood. Commercially pure titanium will be investigated in a second stage as relevant material data becomes available. The response of the iron powder material to stress and temperature will be simulated via an internal variable constitutive model. The model will be calibrated and incorporated in a coupled thermo-mechanical finite element code streamlined for HIP applications. A novel hot triaxial compaction apparatus will be used to provide data for the calibration of the constitutive model. In the final stage, experiments in an industrial scale will be performed to validate the overall HIP predictive capabilities. The primary benefit of this work will be: (a) the capability of assessing the manufacturability of a component via HIP, (b) the design of a container with a minimum number of trial parts, (c) efficient programming of the HIP unit operation schedule as the effect of cycle and workpiece distribution in the unit work zone becomes better understood, and (d) exploration of new products with the potential to influence the design of a new generation of HIP units.

Agency
National Science Foundation (NSF)
Institute
Division of Civil, Mechanical, and Manufacturing Innovation (CMMI)
Application #
9115585
Program Officer
Kevin Lyons
Project Start
Project End
Budget Start
1991-09-01
Budget End
1994-02-28
Support Year
Fiscal Year
1991
Total Cost
$145,250
Indirect Cost
Name
Carnegie-Mellon University
Department
Type
DUNS #
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213