Improvement in Ductility and Fracture Toughness of HIP'd and Isothermally Forged Ti-6Al-6V-2Sn Powder with Heat Treatment.
Abstract
This program was aimed at optimizing the mechanical behavior of powder metallurgy compacts of the Ti-6Al-6V-2Sn alloy. Particular emphasis was placed on breaking-up continuous grain boundary alpha which previous work had indicated was detrimental to the properties of concern, particularly ductility and fracture toughness. A range of microstructures were produced in Hydride-Dehydride and Rotating Electrode Powder Compacts using combinations of hot isostatic pressing, extrusion, isothermal forging and heat treatment. Based on the microstructural studies, two heat treatments were selected and used in combination with powder compaction (Hot isostatic pressing or extrusion) and isothermal forging to develop mechanical properties which were correlated with processing, microstructure and fractographic features. Two types of microstructures were identified as having acceptable levels of strength, ductility and fracture toughness: 1) a high volume fraction of fine equiaxed primary alpha in a matrix of transformed beta and 2) a relatively coarse secondary alpha plate dispersion in combination with a small volume fraction of large low aspect ratio primary alpha. The processing routes necessary to develop structures were defined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1986
- Accession Number
- ADA168804
Entities
People
- Attwell M. Adair
- Daniel Eylon
- Francis H. Froes
- Ronald P. Simpson
Organizations
- Wright Laboratory