scholarly journals Cyclic creep behaviour of two-phase Ti-6Al-2Mo-2Cr alloy

2020 ◽  
Vol 321 ◽  
pp. 11079
Author(s):  
Waldemar Ziaja ◽  
Maciej Motyka ◽  
Krzysztof Kubiak ◽  
Jan Sieniawski
Keyword(s):  
Heat Treatment ◽  
Elevated Temperature ◽  
Titanium Alloys ◽  
Creep Behaviour ◽  
Strong Dependence ◽  
Cyclic Creep ◽  
Tensile Creep ◽  
Two Phase ◽  
Creep Properties ◽  
Cyclic Creep Behaviour

One of the important criteria for selection titanium alloys for discs and blades of turbine engine compressor is their fatigue and creep strength at room and elevated temperature. Fatigue and creep properties of two-phase titanium alloys show strong dependence on microstructure, especially morphology of the α and β phases which can be controlled to certain extent by proper selection of hot working and heat treatment conditions. Quantitative description of two-phase titanium alloys behaviour under loading and environmental conditions leading to combined creep and fatigue processes has been always very challenging task due to large number of factors affecting deformation and fracture behaviour of the material. In the course of the research cyclic creep behaviour of Ti-6Al-2Mo-2Cr alloy (VT3-1) was investigated and compared to low-cycle fatigue and static creep properties at the temperature of 450°C. Microstructure of the alloy was varied by means of the heat treatment. Constant load tensile creep tests were carried out. Tension-tension cyclic loading was applied at the constant stress ratio with and without hold time at maximum load. The effect of test parameters on the creep-fatigue life at elevated temperature was estimated. Characteristic features of fracture surfaces were identified by scanning electron microscopy methods.

scholarly journals Primary Creep Behaviour of Two-Phase Titanium Alloy with Various Microstructure

2016 ◽  
Vol 61 (2) ◽  
pp. 683-688
Author(s):  
W. Ziaja ◽  
M. Motyka ◽  
K. Kubiak ◽  
J. Sieniawski
Keyword(s):  
Heat Treatment ◽  
Elevated Temperature ◽  
Creep Behaviour ◽  
Strong Dependence ◽  
Primary Creep ◽  
Fatigue Properties ◽  
Creep Tests ◽  
Two Phase ◽  
Treatment Conditions ◽  
Primary Creep Strain

Abstract Creep and fatigue properties of two-phase titanium alloys show strong dependence on microstructure, especially morphology of the α and β phases which can be controlled to certain extent by proper selection of hot working and heat treatment conditions. In the paper the creep behaviour of Ti-6Al-2Mo-2Cr alloy (VT3-1) at elevated temperature was modelled. Finite element analyses of primary creep stage were carried out taking into account some microstructural features of the two-phase alloy that were included in the physical model and different properties of α and β phases. In order to verify results of calculations distinct types of microstructure were developed in the alloy by heat treatment and creep tests were carried out at elevated temperature (450°C) at various stress levels. Based on the FEM simulations the effect of changes of some microstructure features on primary creep strain development was estimated.

Microstructure and Creep Properties of AJ62 and AE44 Die-Casting Magnesium Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1546-1551 ◽  
Author(s):  
Andrzej Kiełbus ◽  
Tomasz Rzychoń
Keyword(s):  
Magnesium Alloys ◽  
Creep Resistance ◽  
Cell Structure ◽  
Creep Behaviour ◽  
Die Casting ◽  
Tensile Creep ◽  
Creep Properties ◽  
Die Cast ◽  
Subgrain Formation ◽  
Good Creep Resistance

Microstructure and tensile creep behaviour of the die-cast AE44 and AJ62 magnesium alloys has been studied at temperatures between 175°C and 200°C and at stresses in the range from 60 to 75 MPa. At the 175°C the AJ62 and AE44 alloys exhibit good creep resistance after 120h creep deformation. At 200°C the AE44 alloy shows still good creep resistance, whereas in the case of AJ62 alloy the rapid decreasing of creep resistance has been observed. TEM observations reveal dislocations cell structure in AE44 alloy after creep test. In AJ62 alloy subgrain formation and decreasing the dislocation density have been observed.

Processing, Structure, Texture and Microtexture in Titanium Alloys

2012 ◽  
Vol 710 ◽  
pp. 66-84 ◽  
Author(s):  
Dipankar Banerjee ◽  
Adam L. Pilchak ◽  
James C. Williams
Keyword(s):  
Titanium Alloys ◽  
Single Phase ◽  
Thermomechanical Processing ◽  
Strong Dependence ◽  
Two Phase ◽  
Β Phase ◽  
Phase Fields ◽  
Deformation And Heat Treatment ◽  
Two Phases ◽  
The Individual

We review the effect of processing on structure and texture in titanium alloys, focusing on the understanding of this relationship that has evolved over the last decade. Thermomechanical processing cycles for these alloys involve deformation and heat treatment in single phase β and two phase, α+β, phase fields, and involves a complex interplay between deformation and recrystallization textures of the individual phases, textures arising from the crystallographic relationship between the two phases, and the scale of microstructure evolution. We explore these interactions and trace the strong dependence of thermomechanical pathways on the final structure and texture.

The Creep Behaviour of Extruded Mg-5Li-3Al-1.5Zn-2RE Alloy

2011 ◽  
Vol 213 ◽  
pp. 492-496 ◽  
Author(s):  
Ting Qu Li ◽  
Yong Bing Liu ◽  
Zhan Yi Cao ◽  
Li Ren Cheng ◽  
Dong Mei Jiang
Keyword(s):  
Electron Microscopy ◽  
Creep Behaviour ◽  
Microstructural Analysis ◽  
Extrusion Process ◽  
Intermetallic Phases ◽  
Tensile Creep ◽  
Dislocation Creep ◽  
Creep Tests ◽  
Creep Properties ◽  
Transmission Electron

The Mg-5Li-3Al-1.5Zn-2RE (LaPrCe) alloy was prepared by hot-chamber extrusion process after casting. The alloy consists of α-Mg solid solution and intermetallic phases (Al11RE3 phase and Al2RE phase). The microstructural analysis of the alloy reveals the correlation between microstructure and creep properties. The stress exponent of n varies from 4.25 to 6.23, and the activation energy varies from 104 to 134 kJ/mol. There is a transition between dislocations climb dominated creep mechanism and dislocation creep controlled by non-basal planes slip. Tensile creep tests were combined with detailed transmission electron microscopy in order to characterize the Al11RE3 phase, which had thermal stability at 448K during the creep test. The dislocations pinned and cross-slip dislocations were observed.

Near-Transus Processing (NTP) of Powder Metallurgy Tial-Based Alloys

1994 ◽  
Vol 364 ◽  
Author(s):  
G. E. Fuchs
Keyword(s):  
Heat Treatment ◽  
Elevated Temperature ◽  
Powder Metallurgy ◽  
Intermetallic Compound ◽  
Hot Working ◽  
Engineering Properties ◽  
Creep Properties ◽  
Structural Applications

AbstractAlloys based on the intermetallic compound γ-TiAl are rapidly being developed for elevated temperature structural applications. In order to produce an alloy, by either I/M or P/M techniques, with useful engineering properties, it is necessary to control the microstructure by heat treatment and/or hot working. By combining consolidation with the heat treatment, unique microstructures can be produced in powder metallurgy (P/M) materials. The effect of processing on the microstructures and tensile and creep properties are discussed.

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