Di Qiu^1,3,4, Rongpei Shi^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 1017-1028, 2024, DOI:10.32604/cmes.2024.048797

Abstract For media with inclusions (e.g., precipitates, voids, reinforcements, and others), the difference in lattice parameter and the elastic modulus between the matrix and inclusions cause stress concentration at the interfaces. These stress fields depend on the inclusions’ size, shape, and distribution and will respond instantly to the evolving microstructure. This study develops a phase-field model concerning modulus heterogeneity. The effect of modulus heterogeneity on the growth process and equilibrium state of the α plate in Ti-6Al-4V during precipitation is evaluated. The α precipitate exhibits strong anisotropy in shape upon cooling due to the interplay of the elastic strain and interfacial… More >

Baisen Gao¹, Wei Huang^1,*, Shengnan Wang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-2, 2023, DOI:10.32604/icces.2023.010553

Abstract Additive manufacturing of metallic components can result in initial defects that significantly reduce their mechanical properties [1]. Therefore, there has been considerable interest in studying the fracture and damage behavior of such components through theoretical and experimental studies [2, 3]. Developing a reliable model for predicting the ductile fracture of additively manufactured components is currently of great importance. In this study, we conducted unit cell calculations with the calibration of experimental tests to investigate the ductile fracture of Ti-6Al-4V alloy fabricated through additive manufacturing. The stress triaxiality and Lode parameter were enforced constant for the voided cubic unit cell model… More >

Kang-Hyun Lee¹, Gun Jin Yun^1,2,*

CMC-Computers, Materials & Continua, Vol.66, No.1, pp. 87-112, 2021, DOI:10.32604/cmc.2020.012688

Abstract Re-melting process has been utilized to mitigate the residual stress level in the selective laser melting (SLM) process in recent years. However, the complex consolidation mechanism of powder and the different material behavior after the first laser melting hinder the direct implementation of the re-melting process. In this work, the effects of re-melting on the temperature and residual stress evolution in the SLM process are investigated using a thermo-mechanically coupled finite element model. The degree of consolidation is incorporated in the energy balance equation based on the thermodynamically-consistent phase-field approach. The drastic change of material properties due to the variation… More >

S. Baragetti¹, F. Tordini²

Structural Durability & Health Monitoring, Vol.3, No.3, pp. 165-176, 2007, DOI:10.3970/sdhm.2007.003.165

Abstract The effect of a TiN PVD (Physical Vapor Deposition) coating on the fatigue behaviour of the titanium alloy Ti-6Al-4V was investigated. Fatigue tests were performed on coated and uncoated, both smooth and 120° V-notched, specimens in order to evaluate the influence of the coating on the substrate fatigue resistance. Numerical analyses were carried out in order to determine the stress distributions below the specimen surface and on the coating. Several coating elastic moduli were used in such calculations. The residual stress gradient induced by the coating process deposition and the substrate plasticization were also taken into account with FEM. The… More >

LIU Yong-jie, TIAN Ren-hui, OUYANG Qiao-lin, WANG Qing-yuan

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 5-6, 2011, DOI:10.3970/icces.2011.016.005

Abstract Ti-6Al-4V is widely used in biology engineering as well medical implant. Clinical investigations show that TC4 implant could have rupture of passivation film and visible corrosion. To predict service life of the Ti-6Al-4V implant, it is necessary to study its ultra-high cycle fatigue behaviors in physiological environment exceeding 10⁷ cycles. In this paper, using the ultrasonic fatigue testing technique, the high cycle and ultra-high cycle fatigue properties of Ti-6Al-4V subjection to simulated body fluid (SBF) in body temperature were studied and compared with that of normal Ti-6Al-4V. The experimental results show that SBF subjection has slight influence on the ultra-high… More >

Hideaki NISHIKAWA*, Yoshiyuki FURUYA

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 126-126, 2019, DOI:10.32604/icces.2019.05354

Abstract Fatigue life is determined by microscopic fatigue crack initiation and growth. Since fatigue crack is generally initiated on the slip plane of microstructure and propagated by slip deformation of the crack tip, fatigue life should depends on microstructure. To computationally simulate the effect of microstructure on fatigue property, it is necessary to understand microstructural small fatigue crack initiation and growth behavior. Although Ti-6Al-4V alloy has superior fatigue strength, fatigue strength of forged pancake, used for such as airplane engine, is normally lower than that of rolled alloy. It is possibly comes from microstructural difference, such as micro-texture. However, it is… More >

Fabien Briffod*, Alexandre Bleuset, Takayuki Shiraiwa, Manabu Enoki

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 125-125, 2019, DOI:10.32604/icces.2019.05319

Abstract The fatigue behavior of metallic materials is a multi-scale problem (from a time and length-scale perspective) intimately influenced by microstructural features that determine the early stages of crack propagation. Prediction of fatigue life is traditionally based on the evaluation of macroscopic mechanical fields at the structure level and on the application of empirical rules. However, these structure-oriented methods are material-specific and do not consider the material variability at lower scales. Hence, reliable prediction of fatigue performances and its variability requires on one side the characterization and quantification of early damage mechanisms and on the other side the incorporation of local… More >

Zhao Xilong¹, Zhang Jianxun¹, Chen Hongyuan^1,2, Song Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.6, pp. 557-571, 2013, DOI:10.3970/cmes.2013.092.557

Abstract In order to study failure perspective of Ti-6Al-4V titanium alloy welded joint, fracture behavior of the heat affected zone is researched. Microhardness, tensile test and microstructure are used to study the mechanical properties of the titanium alloy laser welded joint. The tensile and microhardness results show that heat affected zone near the base metal is the weakest in welded joints. This paper is based on the results from in-situ tension test to observe the process of crack expansion in heat affected zone. And then, in-situ test is simulated via the finite element method on ABAQUS Standard; therefore the fracture criteria… More >

Amir Reza Ansari Dezfoli¹, Weng-Sing Hwang^1,2

CMC-Computers, Materials & Continua, Vol.49-50, No.1, pp. 1-11, 2015, DOI:10.3970/cmc.2015.049.001

Abstract Investigations of the microstructural evolution of Titanium (Ti) alloys during high temperature processes and heat treatment are attracting more attention due to wide variety of applications for such alloys. In most of these processes the Titanium alloys are subjected to fast heating or cooling rates. In this paper, Monte Carlo simulation is used to simulate the grain growth kinetics of Ti-6Al-4V alloy during fast heat treatment. Here, Monte Carlo simulation of grain growth is based on the Q-state Potts model. Our model is calibrated using the parabolic grain growth law, dⁿ-d₀ⁿ = kt, where the empirical constants are taken… More >