Numerical Simulations of Tensile Deformation Behavior in Two Phase α2 + γ Lamellar Tial Alloys

1994 ◽  
Vol 364 ◽  
Author(s):  
Bimal K. Kad ◽  
Ming Dao ◽  
Robert J. Asaro
Keyword(s):  
Volume Fraction ◽  
Tensile Deformation ◽  
Hydrostatic Stress ◽  
Fracture Initiation ◽  
Two Phase ◽  
Tial Alloys ◽  
Tensile Deformation Behavior ◽  
Mechanical Methods ◽  
Fully Lamellar ◽  
Stress Buildup

AbstractDeformation microstructures in γ-TiAl + α2Ti3Al based fully lamellar (FL) and nearly lamellar (NL) microstructures have been simulated using micro-mechanical methods. The deformation is extremely inhomogenous resulting in a large accumulation of hydrostatic stresses at the grain boundaries, thereby promoting intergranular fracture initiation. In particular, the increase in ductility with increasing equiaxed γ-grain volume fraction (with compliant deformation characteristics) in nearly lamellar alloys is explained by the reduction of the hydrostatic stress buildup at the boundaries, consequently mitigating fracture.

Factors affecting the lamellar spacing in two-phase TiAl alloys with fully lamellar microstructures

2001 ◽  
Vol 36 (9) ◽  
pp. 1737-1742 ◽  
Author(s):  
Jiancheng Tang ◽  
Baiyun Huang ◽  
Kechao Zhou ◽  
Wensheng Liu ◽  
Yuehui He ◽  
...  
Keyword(s):  
Lamellar Spacing ◽  
Two Phase ◽  
Tial Alloys ◽  
Factors Affecting ◽  
Fully Lamellar

Hall–Petch relationship in two-phase TiAl alloys with fully lamellar microstructures

2002 ◽  
Vol 37 (7) ◽  
pp. 1315-1321 ◽  
Author(s):  
Jiancheng Tang ◽  
Baiyun Huang ◽  
Yuehui He ◽  
Wensheng Liu ◽  
Kechao Zhou ◽  
...  
Keyword(s):  
Two Phase ◽  
Tial Alloys ◽  
Petch Relationship ◽  
Fully Lamellar

Enhanced Strength and Ductility in Hypo-Eutectoid Cu-Al Alloys through ECAP and Annealing

2008 ◽  
Vol 584-586 ◽  
pp. 315-326 ◽  
Author(s):  
Shao Hua Xia ◽  
L.V. Vychigzhanina ◽  
Jing Tao Wang ◽  
Igor V. Alexandrov
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
Tensile Deformation ◽  
Al Alloys ◽  
Optimal Combination ◽  
Tensile Yield Strength ◽  
Angular Pressing ◽  
Tensile Deformation Behavior ◽  
Ultrafine Grained ◽  
Strength And Ductility

In the present investigation, a bimodal structured alloy with ultrafine-grained (UFG) eutectoid matrix embedded with micrometer-grained pre-eutectoid phase was introduced into the hypo-eutectoid Cu-10.8wt.%Al and Cu-11.3wt.%Al alloys by means of pre-pressing heat-treatment, equal-channel-angular pressing (ECAP) and subsequent annealing. Different size of micrometer grained pre-eutectoid phase was obtained by controlling the cooling rate during pre-pressing heat-treatment of the hypo-eutectoid alloy. The tensile deformation behavior of the developed microstructures is characterized by a maximum tensile yield strength up to 800MPa, which is three times higher than that of the un-treated alloy. It is found that the size of the micrometer grained pre-eutectoid phase is critical to the improvement of the bimodal structured alloy. With larger micrometer grained pre-eutectoid phase, no obvious improvement in plastic elongation was observed with the increase of volume fraction of the pre-eutectoid phase from 20% to 40%, but a decrease in the yield tensile strength was observed. An optimal combination of strength and ductility was obtained particularly in those samples embedded with small-sized micrometer-grained pre-eutectoid phase, which provide extra strain gradient hardening effect.

Ultrafine Fully-Lamellar Structures in Two-Phase γ-TiAl Alloys

1996 ◽  
Vol 460 ◽  
Author(s):  
P. J. Maziasz ◽  
C. T. Liu
Keyword(s):  
Room Temperature ◽  
Interlamellar Spacing ◽  
Hot Extrusion ◽  
Processing Parameters ◽  
High Temperature Strength ◽  
Two Phase ◽  
Tial Alloys ◽  
Room Temperature Ductility ◽  
Heat Treated ◽  
Fully Lamellar

ABSTRACTSpecial ultrafine fully-lamellar microstructures have been found recently in γ-TiAl alloys with 46–48 at.% Al, when they are processed or heat-treated above the α-transus temperature (Tα). Hot-extrusion above Tα also produces a refined colony or grain size. Refined-colony/ultrafine-lamellar (RC/UL) microstructures produce an excellent combination of room-temperature ductility and high-temperature strength in Ti-47Al-2Cr-2Nb (at.%) alloys. UL structures generally have an average interlamellar spacing of 100–200 nm, and have regularly alternating γ and α2 lamellea, such that they are dominated by γ/α2 interfaces with relatively few γ/γ twin boundaries. The focus of this study is how variations in processing parameters or alloy composition affect formation of the UL structure, particularly the α2 component.

Role of Equiaxed Primary Alpha (α׳) and Mechanical Properties of Ti-6Al-4V Alloy

2012 ◽  
Vol 510-511 ◽  
pp. 420-428
Author(s):  
A. Ahmad ◽  
A. Ali ◽  
G.H. Awan ◽  
K.M. Ghauri ◽  
R. Aslam
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Volume Fraction ◽  
Lamellar Microstructure ◽  
Phase Region ◽  
Bimodal Microstructure ◽  
Two Phase ◽  
Primary Alpha ◽  
Fully Lamellar

The paper presents the role of equiaxed α׳ in the bimodal microstructure to attain an optimal combination of ductility and strength. The study revealed that the production of bimodal microstructure and volume fraction of equiaxed α׳ were reliant on the forging temperature and subsequent heat treatment. The Ti-6Al-4V alloy was forged in the two phase region and different heat treatment cycles were employed to get the desired bimodal microstructure and thus the combination of strength and ductility. The mechanical properties of fully lamellar microstructure were compared with bimodal microstructure containing equiaxed α׳. The experimental results showed that the amount of equiaxed α׳ in the bimodal microstructure was critical for achieving a well-balanced profile of mechanical properties.

Modeling of the Tensile Deformation Behavior of SiCp/Fe Composites

2012 ◽  
Vol 217-219 ◽  
pp. 79-85
Author(s):  
Yao Mian Wang ◽  
Huan Ping Yang ◽  
Cong Hui Zhang
Keyword(s):  
Particle Size ◽  
Deformation Behavior ◽  
Volume Fraction ◽  
Tensile Deformation ◽  
Equivalent Inclusion Method ◽  
Particle Cracking ◽  
Equivalent Inclusion ◽  
Tensile Deformation Behavior ◽  
The Matrix ◽  
Dislocation Strengthening

A combined model taking account of the dislocation strengthening effects and particle cracking during tensile straining based on Eshelby equivalent inclusion method is presented to model the deformation behavior of SiCp/Fe composites. Stress-strain curves of the composites were simulated and it is found that the curves vary obviously with the volume fraction and particle size. The yield stress is increased significantly by increasing the volume fraction and decreasing the particle size. Stress in particles is very high during straining and the fraction of cracked particles increased obviously with increasing the particle size. These results indicate that higher volume fraction and finer particles can give better mechanical properties of the composites attributed to the increased load sharing effect and dislocation strengthening effects of the matrix.

Effect of internal pores on tensile properties of Co-Cr-Mo alloy fabricated by selective laser melting

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hyeon-Tae Im ◽  
Hyun-Su Kang ◽  
Hyeon-Goo Kang ◽  
Hyo Kyu Kim ◽  
Jun Choi ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Selective Laser Melting ◽  
Volume Fraction ◽  
Tensile Deformation ◽  
Hot Isostatic Pressing ◽  
Tensile Tests ◽  
Laser Melting ◽  
Content Type ◽  
Tensile Deformation Behavior ◽  
Ε Phase

Purpose The purpose of this paper is to examine the effect of internal pores on the tensile properties of a Co–Cr–Mo alloy fabricated by selective laser melting (SLM). Design/methodology/approach The size and volume fraction of pores were controlled through high temperature annealing (HTA) and hot isostatic pressing (HIP). Findings After HTA, the size and fraction of pores decreased compared with the as-built SLM sample, and no pores were observed after HIP. Tensile tests of the HTA and HIP samples showed nearly similar tensile deformation behavior. From the results, the authors found that the size of the internal pores formed in the SLM process had little effect on the tensile properties. The as-built SLM sample had less elongation than the HTA and HIP samples, which would not the effect of porosity, but rather the effect of the residual stress and the retained ε phase after the SLM process. Originality/value Although pores are a main factor that influence the mechanical properties, the effect of pores on the tensile properties of Co–Cr–Mo alloys fabricated by SLM has not been studied. Therefore, in this study, the effect of pores on the tensile properties of a Co–Cr–Mo alloy fabricated by SLM was studied.

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