The effects of forging and rolling on microstructure in O+BCC Ti-Al-Nb alloys

Research output: Contribution to journalArticle

  • 38 Citations

Abstract

The effects of hot upset forging and hot pack rolling on microstructure of orthorhombic (O)+body-centered cubic (BCC) Ti-Al-Nb alloys was investigated. The starting materials were melted ingots of nominal compositions: Ti-25Al-25Nb(at.%), Ti-23Al-27Nb(at.%), and Ti-12Al-38Nb(at.%). Smaller cigar-shaped Ti-25Al-25Nb ingots were examined to understand the effect of rolling preheat treatment on microstructure. It was found that super-transus preheat treatment results in large prior BCC grains and surface edge cracking. For larger castings, forging and rolling procedures were carried out after heating the materials between 932-1000°C. These temperatures were below the BCC-transus temperature for Ti-23Al-27Nb and Ti-25Al-25Nb and above the transus for Ti-12Al-38Nb. This resulted in a significantly larger grain size for the as-processed Ti-12Al-38Nb compared with the other two alloys. The Ti-25Al-25Nb alloy required the greatest forging and rolling loads, while the fully-BCC Ti-12Al-38Nb alloy exhibited the best workability and required the lowest forging and rolling loads. This was related to the alloys' aluminum contents and O-phase volume fractions. Sub-transus processing of the near Ti2AlNb alloys proved to be a viable technique for obtaining homogeneous microstructures containing fine O and BCC phases and lacking large prior BCC grains, which can be detrimental to the mechanical performance.

Original languageEnglish (US)
Pages (from-to)118-129
Number of pages12
JournalMaterials Science and Engineering A
Volume279
Issue number1-2
StatePublished - Feb 29 2000
Externally publishedYes

Profile

HMGN2 Protein
Forging
Microstructure
forging
microstructure
Acetanilides
Traffic Accidents
Non-Small Cell Lung Carcinoma
Ingots
Temperature
ingots
temperature
Edema Disease of Swine
Lactation Disorders
African horse sickness virus
Aprindine
Iduronidase
Accessory Nerve
Heating
Hot rolling

Keywords

  • BCC phases
  • Orthorhombic phase
  • Titanium alloys

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

The effects of forging and rolling on microstructure in O+BCC Ti-Al-Nb alloys. / Boehlert, C. J.

In: Materials Science and Engineering A, Vol. 279, No. 1-2, 29.02.2000, p. 118-129.

Research output: Contribution to journalArticle

Boehlert, C. J. / The effects of forging and rolling on microstructure in O+BCC Ti-Al-Nb alloys.

In: Materials Science and Engineering A, Vol. 279, No. 1-2, 29.02.2000, p. 118-129.

Research output: Contribution to journalArticle

@article{341c6207bf9b42a78042cf90615f3b50,
title = "The effects of forging and rolling on microstructure in O+BCC Ti-Al-Nb alloys",
abstract = "The effects of hot upset forging and hot pack rolling on microstructure of orthorhombic (O)+body-centered cubic (BCC) Ti-Al-Nb alloys was investigated. The starting materials were melted ingots of nominal compositions: Ti-25Al-25Nb(at.%), Ti-23Al-27Nb(at.%), and Ti-12Al-38Nb(at.%). Smaller cigar-shaped Ti-25Al-25Nb ingots were examined to understand the effect of rolling preheat treatment on microstructure. It was found that super-transus preheat treatment results in large prior BCC grains and surface edge cracking. For larger castings, forging and rolling procedures were carried out after heating the materials between 932-1000°C. These temperatures were below the BCC-transus temperature for Ti-23Al-27Nb and Ti-25Al-25Nb and above the transus for Ti-12Al-38Nb. This resulted in a significantly larger grain size for the as-processed Ti-12Al-38Nb compared with the other two alloys. The Ti-25Al-25Nb alloy required the greatest forging and rolling loads, while the fully-BCC Ti-12Al-38Nb alloy exhibited the best workability and required the lowest forging and rolling loads. This was related to the alloys' aluminum contents and O-phase volume fractions. Sub-transus processing of the near Ti2AlNb alloys proved to be a viable technique for obtaining homogeneous microstructures containing fine O and BCC phases and lacking large prior BCC grains, which can be detrimental to the mechanical performance.",
keywords = "BCC phases, Orthorhombic phase, Titanium alloys",
author = "Boehlert, {C. J.}",
year = "2000",
month = "2",
volume = "279",
pages = "118--129",
journal = "Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing",
issn = "0921-5093",
publisher = "Elsevier BV",
number = "1-2",

}

TY - JOUR

T1 - The effects of forging and rolling on microstructure in O+BCC Ti-Al-Nb alloys

AU - Boehlert,C. J.

PY - 2000/2/29

Y1 - 2000/2/29

N2 - The effects of hot upset forging and hot pack rolling on microstructure of orthorhombic (O)+body-centered cubic (BCC) Ti-Al-Nb alloys was investigated. The starting materials were melted ingots of nominal compositions: Ti-25Al-25Nb(at.%), Ti-23Al-27Nb(at.%), and Ti-12Al-38Nb(at.%). Smaller cigar-shaped Ti-25Al-25Nb ingots were examined to understand the effect of rolling preheat treatment on microstructure. It was found that super-transus preheat treatment results in large prior BCC grains and surface edge cracking. For larger castings, forging and rolling procedures were carried out after heating the materials between 932-1000°C. These temperatures were below the BCC-transus temperature for Ti-23Al-27Nb and Ti-25Al-25Nb and above the transus for Ti-12Al-38Nb. This resulted in a significantly larger grain size for the as-processed Ti-12Al-38Nb compared with the other two alloys. The Ti-25Al-25Nb alloy required the greatest forging and rolling loads, while the fully-BCC Ti-12Al-38Nb alloy exhibited the best workability and required the lowest forging and rolling loads. This was related to the alloys' aluminum contents and O-phase volume fractions. Sub-transus processing of the near Ti2AlNb alloys proved to be a viable technique for obtaining homogeneous microstructures containing fine O and BCC phases and lacking large prior BCC grains, which can be detrimental to the mechanical performance.

AB - The effects of hot upset forging and hot pack rolling on microstructure of orthorhombic (O)+body-centered cubic (BCC) Ti-Al-Nb alloys was investigated. The starting materials were melted ingots of nominal compositions: Ti-25Al-25Nb(at.%), Ti-23Al-27Nb(at.%), and Ti-12Al-38Nb(at.%). Smaller cigar-shaped Ti-25Al-25Nb ingots were examined to understand the effect of rolling preheat treatment on microstructure. It was found that super-transus preheat treatment results in large prior BCC grains and surface edge cracking. For larger castings, forging and rolling procedures were carried out after heating the materials between 932-1000°C. These temperatures were below the BCC-transus temperature for Ti-23Al-27Nb and Ti-25Al-25Nb and above the transus for Ti-12Al-38Nb. This resulted in a significantly larger grain size for the as-processed Ti-12Al-38Nb compared with the other two alloys. The Ti-25Al-25Nb alloy required the greatest forging and rolling loads, while the fully-BCC Ti-12Al-38Nb alloy exhibited the best workability and required the lowest forging and rolling loads. This was related to the alloys' aluminum contents and O-phase volume fractions. Sub-transus processing of the near Ti2AlNb alloys proved to be a viable technique for obtaining homogeneous microstructures containing fine O and BCC phases and lacking large prior BCC grains, which can be detrimental to the mechanical performance.

KW - BCC phases

KW - Orthorhombic phase

KW - Titanium alloys

UR - http://www.scopus.com/inward/record.url?scp=0004141768&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0004141768&partnerID=8YFLogxK

M3 - Article

VL - 279

SP - 118

EP - 129

JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

T2 - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

SN - 0921-5093

IS - 1-2

ER -