Microstructure evolution, hot deformation behavior and mechanical properties of Ti-43Al-6Nb-1B alloy

H. Z. Niu; Y. Y. Chen; F. T. Kong; J. P. Lin

doi:10.1016/j.intermet.2012.07.016

Microstructure evolution, hot deformation behavior and mechanical properties of Ti-43Al-6Nb-1B alloy

H. Z. Niu
, Y. Y. Chen^*
, F. T. Kong
, J. P. Lin

^*Corresponding author for this work

School of Materials Science and Engineering

Harbin Institute of Technology
University of Science and Technology Beijing

Research output: Contribution to journal › Article › peer-review

68 Scopus citations

Abstract

A novel high Nb, low Al contained TiAl alloy Ti-43Al-6Nb-1B (at %) was fabricated by induction skull melting (ISM) technique. The as-cast alloy exhibits fully lamellar (FL) microstructure with mean colony size of 90 μm. By means of thermophysical simulation, the hot deformation mechanism at 1250 °C is concluded as dislocation slip and twinning in γ phase; bending, rotating and elongation of lamellar colonies are the primary deformation modes. A large-size TiAl pancake was successfully produced by triple-step canned forging at 1250 °C. The forged alloy displays duplex (DP) microstructure consisting of elongated lamellar colonies and γ grains. Typical DP and FL microstructures were further obtained by different heat treatments. The tensile strength increases rapidly from 670 MPa in as-cast state to 975 MPa in as-forged condition at room temperature, with elongation increasing from 0.4% to 1.5%. The as-forged alloy maintains strength higher than 950 MPa until 750 °C; also the DP and FL materials hold excellent strength more than 830 MPa and 770 MPa respectively. The superior tensile properties after forging are mainly ascribed to the microstructure refinement and homogenization, the lamellar spacing reducing, as well as the low Al and relatively low Nb additions in this novel high Nb containing TiAl alloy. Crown

Original language	English
Pages (from-to)	249-256
Number of pages	8
Journal	Intermetallics
Volume	31
DOIs	https://doi.org/10.1016/j.intermet.2012.07.016
State	Published - Dec 2012

Keywords

A. Titanium aluminides, based on TiAl
B. Mechanical properties at ambient temperature
B. Mechanical properties at high temperatures
C. Isothermal forging
D. Microstructure

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10.1016/j.intermet.2012.07.016

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title = "Microstructure evolution, hot deformation behavior and mechanical properties of Ti-43Al-6Nb-1B alloy",

abstract = "A novel high Nb, low Al contained TiAl alloy Ti-43Al-6Nb-1B (at \%) was fabricated by induction skull melting (ISM) technique. The as-cast alloy exhibits fully lamellar (FL) microstructure with mean colony size of 90 μm. By means of thermophysical simulation, the hot deformation mechanism at 1250 °C is concluded as dislocation slip and twinning in γ phase; bending, rotating and elongation of lamellar colonies are the primary deformation modes. A large-size TiAl pancake was successfully produced by triple-step canned forging at 1250 °C. The forged alloy displays duplex (DP) microstructure consisting of elongated lamellar colonies and γ grains. Typical DP and FL microstructures were further obtained by different heat treatments. The tensile strength increases rapidly from 670 MPa in as-cast state to 975 MPa in as-forged condition at room temperature, with elongation increasing from 0.4\% to 1.5\%. The as-forged alloy maintains strength higher than 950 MPa until 750 °C; also the DP and FL materials hold excellent strength more than 830 MPa and 770 MPa respectively. The superior tensile properties after forging are mainly ascribed to the microstructure refinement and homogenization, the lamellar spacing reducing, as well as the low Al and relatively low Nb additions in this novel high Nb containing TiAl alloy. Crown",

keywords = "A. Titanium aluminides, based on TiAl, B. Mechanical properties at ambient temperature, B. Mechanical properties at high temperatures, C. Isothermal forging, D. Microstructure",

author = "Niu, \{H. Z.\} and Chen, \{Y. Y.\} and Kong, \{F. T.\} and Lin, \{J. P.\}",

year = "2012",

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doi = "10.1016/j.intermet.2012.07.016",

language = "英语",

volume = "31",

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journal = "Intermetallics",

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T1 - Microstructure evolution, hot deformation behavior and mechanical properties of Ti-43Al-6Nb-1B alloy

AU - Niu, H. Z.

AU - Chen, Y. Y.

AU - Kong, F. T.

AU - Lin, J. P.

PY - 2012/12

Y1 - 2012/12

N2 - A novel high Nb, low Al contained TiAl alloy Ti-43Al-6Nb-1B (at %) was fabricated by induction skull melting (ISM) technique. The as-cast alloy exhibits fully lamellar (FL) microstructure with mean colony size of 90 μm. By means of thermophysical simulation, the hot deformation mechanism at 1250 °C is concluded as dislocation slip and twinning in γ phase; bending, rotating and elongation of lamellar colonies are the primary deformation modes. A large-size TiAl pancake was successfully produced by triple-step canned forging at 1250 °C. The forged alloy displays duplex (DP) microstructure consisting of elongated lamellar colonies and γ grains. Typical DP and FL microstructures were further obtained by different heat treatments. The tensile strength increases rapidly from 670 MPa in as-cast state to 975 MPa in as-forged condition at room temperature, with elongation increasing from 0.4% to 1.5%. The as-forged alloy maintains strength higher than 950 MPa until 750 °C; also the DP and FL materials hold excellent strength more than 830 MPa and 770 MPa respectively. The superior tensile properties after forging are mainly ascribed to the microstructure refinement and homogenization, the lamellar spacing reducing, as well as the low Al and relatively low Nb additions in this novel high Nb containing TiAl alloy. Crown

AB - A novel high Nb, low Al contained TiAl alloy Ti-43Al-6Nb-1B (at %) was fabricated by induction skull melting (ISM) technique. The as-cast alloy exhibits fully lamellar (FL) microstructure with mean colony size of 90 μm. By means of thermophysical simulation, the hot deformation mechanism at 1250 °C is concluded as dislocation slip and twinning in γ phase; bending, rotating and elongation of lamellar colonies are the primary deformation modes. A large-size TiAl pancake was successfully produced by triple-step canned forging at 1250 °C. The forged alloy displays duplex (DP) microstructure consisting of elongated lamellar colonies and γ grains. Typical DP and FL microstructures were further obtained by different heat treatments. The tensile strength increases rapidly from 670 MPa in as-cast state to 975 MPa in as-forged condition at room temperature, with elongation increasing from 0.4% to 1.5%. The as-forged alloy maintains strength higher than 950 MPa until 750 °C; also the DP and FL materials hold excellent strength more than 830 MPa and 770 MPa respectively. The superior tensile properties after forging are mainly ascribed to the microstructure refinement and homogenization, the lamellar spacing reducing, as well as the low Al and relatively low Nb additions in this novel high Nb containing TiAl alloy. Crown

KW - A. Titanium aluminides, based on TiAl

KW - B. Mechanical properties at ambient temperature

KW - B. Mechanical properties at high temperatures

KW - C. Isothermal forging

KW - D. Microstructure

UR - https://www.scopus.com/pages/publications/84866993601

U2 - 10.1016/j.intermet.2012.07.016

DO - 10.1016/j.intermet.2012.07.016

M3 - 文章

AN - SCOPUS:84866993601

SN - 0966-9795

VL - 31

SP - 249

EP - 256

JO - Intermetallics

JF - Intermetallics

ER -

Microstructure evolution, hot deformation behavior and mechanical properties of Ti-43Al-6Nb-1B alloy

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Keywords

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