Synthesis, microstructure and mechanical properties of bulk ultrafine grained Ti-47Al-2Cr (at%) alloy
type: CreativeWork
description: Hot isostatic pressing (HIP) and powder compact forging of Ti/Al/Cr composite powders of composition Ti-47Al-2Cr (at%) have been carried out to synthesize bulk ultrafine grained Ti-47Al-2Cr alloy. The Ti/Al/Cr composite powders were produced using high energy mechanical milling of elemental Ti, Al, Cr powders in a retsch planetary mill. The microstructure and mechanical properties of the bulk consolidated alloy produced using different processing techniques has been investigated. The mechanical properties of the alloy were studied in tension and compression both at room and elevated temperatures especially to know the formability of the material. The bulk alloy samples produced by HIP for 2 hours at 1000 degrees C had porosity of approximately ~ 5%, indicating that the HIP time was not sufficient to close the pores. The microstructure mainly consisted of TiAl as the major phase and Ti(Al) and Ti3Al as minors, the unreacted Ti(Al) phase in the microstructure was mainly due to the initial powder condition, in which a small fraction of powder particles were rich in Ti. Tensile testing of the alloy samples was carried out at different temperatures. At room temperature the alloy was fairly brittle, without any plastic deformation, and had a fracture strength of ~ 100 MPa. At elevated temperatures the samples became ductile, as reflected by considerable amounts of tensile elongations at 800 degrees C and above. The maximum amount of elongation was found to be between 70 - 80% at 900 degrees C. The tensile yield strength at 800 degrees C was in the range of 84-90 MPa and decreased to 55-58 MPa with the testing temperature of the samples to 900 degrees C. In compression the alloy showed plastic yielding and yield strength of ~ 1.4 GPa at room temperature. Compression testing at 900 degrees C revealed that compressive deformations equivalent to a height reduction of 50% could be easily achieved without cracking. Direct powder compact forging using canned powder compacts of t…
abstract: Hot isostatic pressing (HIP) and powder compact forging of Ti/Al/Cr composite powders of composition Ti-47Al-2Cr (at%) have been carried out to synthesize bulk ultrafine grained Ti-47Al-2Cr alloy. The Ti/Al/Cr composite powders were produced using high energy mechanical milling of elemental Ti, Al, Cr powders in a retsch planetary mill. The microstructure and mechanical properties of the bulk consolidated alloy produced using different processing techniques has been investigated. The mechanical properties of the alloy were studied in tension and compression both at room and elevated temperatures especially to know the formability of the material. The bulk alloy samples produced by HIP for 2 hours at 1000 degrees C had porosity of approximately ~ 5%, indicating that the HIP time was not sufficient to close the pores. The microstructure mainly consisted of TiAl as the major phase and Ti(Al) and Ti3Al as minors, the unreacted Ti(Al) phase in the microstructure was mainly due to the initial powder condition, in which a small fraction of powder particles were rich in Ti. Tensile testing of the alloy samples was carried out at different temperatures. At room temperature the alloy was fairly brittle, without any plastic deformation, and had a fracture strength of ~ 100 MPa. At elevated temperatures the samples became ductile, as reflected by considerable amounts of tensile elongations at 800 degrees C and above. The maximum amount of elongation was found to be between 70 - 80% at 900 degrees C. The tensile yield strength at 800 degrees C was in the range of 84-90 MPa and decreased to 55-58 MPa with the testing temperature of the samples to 900 degrees C. In compression the alloy showed plastic yielding and yield strength of ~ 1.4 GPa at room temperature. Compression testing at 900 degrees C revealed that compressive deformations equivalent to a height reduction of 50% could be easily achieved without cracking. Direct powder compact forging using canned powder compacts of t…
author: Nadakuduru, Vijay Navaratna
keywords: ultrafine grained, TiAl based alloys, mechanical properties, hot isostatic pressing, powder compact forging
date published: 2009
date modified: 2026-07-24T05:57:38Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato