Accession Number:

ADA523372

Title:

Hot Rolling of Gamma Titanium Aluminide Foil (PREPRINT)

Descriptive Note:

Journal article

Corporate Author:

AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH METALS, CERAMICS AND NONDESTRUCTIVE EVALUATION DIVISION

Report Date:

2010-04-01

Pagination or Media Count:

36.0

Abstract:

Metal flow and microstructure evolution during the thermomechanical processing of thin-gage foil of a near-gamma titanium-aluminide alloy, Ti-45.5Al-2Cr-2Nb, with an equiaxed-gamma microstructure was investigated experimentally and theoretically. Foils of thickness of 200 - 250 micrometers were fabricated via hot rolling of sheet in a can of proprietary design. The variation in gage of the rolled foils was -15 micrometers except in very sporadic local areas with variations of approximately 60 micrometers relative to the mean. Metallography revealed that the larger thickness variations were associated with large remnant colonies lying in a hard orientation for deformation. To rationalize these observations, a self-consistent model was used to estimate the strain partitioning between the softer equiaxed-gamma matrix and the remnant colonies. Furthermore, the efficacy of pre- or post- rolling heat treatment in eliminating remnant colonies was demonstrated and quantified using a static-spheroidization model. The elimination of remnant colonies via spheroidization prior to foil rolling gave rise to improved gage control.

Subject Categories:

  • Fabrication Metallurgy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE