The Effects of the Oxygen-enriched Surface Layer on Mechanical Properties of α+β Type Titanium Alloys
スポンサーリンク
概要
- 論文の詳細を見る
The effects of heat treating conditions on thickness of the oxygen-enriched layer or α-case in Ti-4.5%Al-3%V-2%Fe-2%Mo alloy were studied in comparison with Ti-6%Al-4%V alloy, and then the effects of these layers on the mechanical properties were investigated. The higher heating temperature and an extended heating time increased oxygen-enriched layer or α-case thickness in Ti-4.5%Al-3%V-2%Fe-2%Mo alloy, and atmospheric heating using high purity argon gas with 99.999% purity could not prevent formation of the oxygen-enriched layer even by heating at such a low temperature as 998 K. The 30 μm thick oxygen-enriched layer without α-case was formed by heat treating at 1048 K for 3.6 ks in use of 99.9% purity argon gas which corresponded to the typical heating conditions adopted in a practical superplastic forming (SPF) operation using Ti-4.5%Al-3%V-2%Fe-2%Mo alloy. The thickness of both surface layers in Ti-6%Al-4%V alloy was much thicker than Ti-4.5%Al-3%V-2%Fe-2%Mo alloy because of its higher heating temperature. Tensile elongation, fatigue strength and bendability were deteriorated with the increase of oxygen-enriched layer or α-case thickness, and removal of these layers by pickling treatment fully recovered these properties to an original level. Deterioration of the mechanical properties was exerted by existence of the surface layer with high hardness, and in particular, the oxygen-enriched layer with α-case decreased fatigue strength more pronouncedly compared with the surface layer without α-case. Existence of brittle surface layer with high hardness and the coarse grain size in α-case appeared to be responsible for accelerated formation of microcrack at the surface of the mechanical testing specimens, resulting in deterioration of various properties.
- 2005-01-15
著者
-
Ouchi C
Department Of Materials Processing Tohoku University
-
Ouchi Chiaki
Tohoku University
-
Minakawa Kuni-nori
Jfe Steel Corporation
-
Ouchi Chiaki
Department Of Metallurgy Tohoku University
-
FUKAI Hideaki
JFE Steel Corporation
-
IIZUMI Hiroshi
JFE Steel Corporation
-
Ouchi Chiaki
Department Of Materials Processing Graduate School Of Engineering Tohoku University
関連論文
- Surface Hardening Treatment for Titanium Materials Using Ar-5%CO Gas in Combination with Post Heat Treatment under Vacuum
- Boron and Nitrogen in GaAs and InP Melts Equilibrated with B_2O_3 Flux
- Behavior of Oxygen in Ga-As Melts with the Range of As Content up to 5 mass % Equilibrated with B_2O_3 Flux
- Dynamic and Static Restoration Behaviors of Pure Lead and Tin in the Ambient Temperature Range
- The Effect of Solute Elements on Hardness and Grain Size in Platinum Based Binary Alloys
- Development of a New Method for Manufacturing Iron Foam Using Gases Generated by Reduction of Iron Oxide
- Hydrothermal Synthesis of Zeolite A Using Blast Furnace Slag
- The Effects of the Oxygen-enriched Surface Layer on Mechanical Properties of α+β Type Titanium Alloys
- Development of Steel Plates by Intensive Use of TMCP and Direct Quenching Processes
- Fatigue Behaviors of Ultra Fine Wires of β-Type and α-Type Titanium Alloys
- Oxidation or Nitridation Behavior of Pure Chromium and Chromium Alloys Containing 10mass%Ni or Fe in Atmospheric Heating
- Alloy Design and Property Evaluation of New β Type Titanium Alloy with Excellent Cold Workability and Biocompatibility
- Preparation of Calcium Phosphate Films by Radiofrequency Magnetron Sputtering
- Grain Refinement of As Cast Austenite by Dynamic Recrystallization in HSLA Steels
- Solubilities and Equilibrium Distribution Coefficients of Oxygen and Carbon in Silicon
- Alloy Design and Properties of New α+β Titanium Alloy with Excellent Cold Workability, Superplasticity and Cytocompatibility
- Evaluation of Sliding Wear Resistant Property of C. P. Titanium and SP-700 Titanium Alloy Surface-hardened by Ar-5%CO Gas
- Variations in the Microstructure and Hardness with Solution Treating and Aging Conditions in New α+β Titanium Alloy Ti-4.5%Al-6%Nb-2%Fe-2%Mo
- β Grain Refinement due to Small Amounts of Yttrium Addition in α+β Type Titanium Alloy, SP-700
- Austenitic Grain Growth behavior Immediately after Dynamic Recrystallization in HSLA Steels and Austenitic Stainless Steel
- Surface Hardening Treatment for C.P. Titanium and Titanium Alloys in Use of Ar-5%CO Gas
- Effects of Dynamic Recrystallization on γ Grain Refinement and Improvement of Micro Segregation of As Cast Austenite in 9%Ni Steel
- Strength-Ductility Relationship in Solution Treated and Aged α+β Type Ti-4.5%Al-3%V-2%Fe-2%Mo Titanium Alloy
- Effect of β Phase Stability at Room Temperature on Mechanical Properties in β-Rich α+β Type Ti-4.5Al-3V-2Mo-2Fe Alloy
- Effect of Al on ω phase transformation behavior in Ti-8V-5Fe-(1-3)Al alloy
- Effect of Cooling Rate on Microstructure and Fracture Characteristics of β-Rich α+β Type Ti-4.5Al-3V-2Mo-2Fe Alloy
- Alkali Hydrothermal Synthesis of Zeolite A Using Oxide By-products
- Recovery of Calcium from BF Slag and Synthesis of Zeolite A Using Its Residue