|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Influence of alloy element partitioning on strength of primary α phase in Ti-6Al-4V alloy显示文摘The partitioning effect of Al(α-phase stabilizer) and V elements(β-phase stabilizer) on strength of the primary α phases in the α/β Ti-6 Al-4 V alloy with the bimodal microstructure was investigated.It was found that partitioning of Al and V elements took place in the Ti-6 Al-4 V alloy during the recrystallization process,leading to the variation of the content of Al and V elements in the primary α phases with changing the volume fraction of the primary α phase.Nanoindentation tests reveal a general trend that the strength of the primary α phases increases with decreasing the volume fraction of the primary α phases,and such trend is independent on the loading direction relative to the c-axis of the α phase.The enhanced strength is attributed to the increase of the content of Al element in the primary α phase,but it is not dominated evidently by the change of the V content.The solid solution strengthening contributed from both the elastic strain introduced by the solute atoms and the variation of the density of states was estimated theoretically. | L.R.Zeng H.L.Chen X.Li L.M.Lei G.P.Zhang | 2018 | Journal of Materials Science & Technology2018，34，5： | 6 |
| 2 | Geometrical Scale-Sensitive Fatigue Properties of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloys With α/β Lamellar Microstructures显示文摘Fatigue properties of the Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy sheets containing different numbers of α/β Widmansttten colonies in the thickness direction of the sheets were investigated by tensionetension fatigue testing. It is found that fatigue properties of the Ti alloy either in low- or high-stress amplitude regimes become more sensitive to the sheet thickness of the Ti alloy as the sheet thickness is comparable to the length scale of the Widmansttten colonies. The basic mechanism of such length scale-sensitive fatigue properties in the Ti alloy was elucidated. | B.Zhang Z.M.Song L.M.Lei L.Kang G.P.Zhang | 2014 | Journal of Materials Science & Technology2014，30，12： | 4 |
| 3 | Toward an understanding of dwell fatigue damage mechanism of bimodal Ti-6Al-4V alloys显示文摘Dwell fatigue effect is a long-standing problem threatening the long-term service reliability for fan blades and fan disks of an aircraft engine.To understand the basic mechanism of dwell fatigue damage,pure fatigue and 60 s dwell fatigue properties of bimodal Ti-6Al-4V alloys with different volume fractions of the primaryα(α_(p))phase were examined comparatively.The results showed that both pure fatigue and dwell fatigue life decreased with increasing the volume fraction of theα_(p)phase and the dwell fatigue life was lower than the pure fatigue one.The quasi-in-situ test results and the quantitative characterization of damage behaviors of the local microstructure units defined by theα_(p)-secondaryα(α_(s))combination reveal that theα_(s)phase close to theα_(p)phase with extensively slip activities was gradually damaged under dwell fatigue loading,while that under pure fatigue loading was undamaged,demonstrating that the dwell loading induced the damage of theα_(s)phase,and further reduced the fatigue life.A stress relaxation-based model is proposed to describe the physical mechanism on dwell fatigue damage of the bimodal Ti-6Al-4V alloy,i.e.the elastic deformation of theα_(s)phase caused by the strain incompatibility would be gradually transformed into plastic deformation during the dwell stage,and thus promotes fatigue damage.The model provides new insights into the microscopic process of stress/strain transfer between the soft and hard microstructure units under dwell fatigue loading. | L.R.Zeng L.M.Lei X.M.Luo G.P.Zhang | 2022 | Journal of Materials Science & Technology2022，，13： | 1 |
| 4 | Toward developing Ti alloys with high fatigue crack growth resistance by additive manufacturing显示文摘Fatigue crack growth behaviors were investigated by three-point bending tests for TA19 alloy fabricated by laser metal deposition and four kinds of heat-treated samples.The crack growth resistance of the TA19 samples in the near-threshold regime and Paris regime was evaluated through the experimental characterization and theoretical analysis of the interaction between fatigue crack andα/βphase inter-face,columnar prior-βgrain boundary and colony boundary.The results show that in the near-threshold regime,the fatigue crack propagation threshold and resistance increase with the increase of widths of lamellarαp phases and colonies,and the decrease of the number ofαlaths with an angle(ϕ)relative to the applied stress direction ranging from 75°to 90°.In the Paris regime,the fatigue cracking path can be deflected at colony boundaries or columnar prior-βgrain boundaries.The larger the deflection angle,the more tortuous the cracking path and the lower the fatigue crack growth rate.The angle(γ)of the columnar prior-βgrain growth direction relative to the build direction affects not onlyϕof differentαvariants,but also the fatigue cracking path deflection angle(θij)at columnar prior-βgrain boundaries.An optimal combination ofγ=0°-15°-0°-15°for several adjacent columnar prior-βgrains is derived from the theoretical analysis,and that can effectively avoidϕbeing in the range from 75°to 90°and makeθij as large as possible.Such findings provide a guide for the selection of scanning strategies and process parameters to additively manufacture Ti alloys with high fatigue damage tolerance. | F.Wang L.M.Lei X.Fu L.Shi X.M.Luo Z.M.Song G.P.Zhang | 2023 | Journal of Materials Science & Technology2023，，1： | 1 |
| 5 | Toward qualification of additively manufactured metal parts:Tensile and fatigue properties of selective laser melted Inconel 718 evaluated using miniature specimens显示文摘Combined with the topology optimization,additive manufacturing can be used to fabricate metal parts with complex shapes.However,due to the geometrical variations and microstructure heterogeneities of the additively manufactured metal parts,new standards with the use of miniature specimens are required for the evalutation of the spatial distribution of mechanical properties throughout the parts.Here,we conduct a systematic investigation on tensile and fatigue properties of selective laser melted Inconel718 specimens with different thicknesses ranging from 0.1 mm to 1 mm.A“microstructure unit”that can well reflect the microstructure characteristic of selective laser melted materials is defined.The results reveal that premature necking with a dramatic drop in uniform elongation occurs if the ratio(t/d)of specimen thickness(t)to the'microstructure unit'size(d)is less than one.Premature necking is mainly attributed to the transition of strain localization behavior.We also propose a probabilistic statistical model for fatigue limit prediction based on the available fatigue data.It is recommended that the criterion of t/d≥4 should be satisfied to ensure that the yield strength,the uniform elongation,and the fatigue limit determined by the miniature specimens are comparable with those determined by standard specimens.The findings may provdie a guide to the establishment of miniature specimen-based standards toward the qualification of additively manufactured metal parts. | H.Y.Wan W.K.Yang L.Y.Wang Z.J.Zhou C.P.Li G.F.Chen L.M.Lei G.P.Zhang | 2022 | Journal of Materials Science & Technology2022，，2： | 1 |
| 6 | Laser additive manufacturing of strong and ductile Al-12Si alloy under static magnetic field显示文摘Rapid cooling and solidification during laser additive manufacturing(LAM)can produce ultra-fine microstructure with higher strength.However,the non-uniform cell/grain structure can easily result in early stress concentration and fracture during deformation,which remains a major challenge for the LAM field.Using Al-12Si as the model alloy,we employed the external static magnetic field(SMF)to modulate the laser powder bed fusion process(L-PBF),demonstrating a uniform microstructure with a refined cell structure.The mechanical properties show that the SMF can produce a combination of high tensile strength of 451.4±0.5 MPa and large uniform elongation of 10.4%±0.79%,which are superior to those of previously-reported Al-Si alloys with post-treatment or element alloying.The mechanism analysis based on multi-scale simulation reveals the determining role of SMF in rapid solidification,and this method is applicable to the microstructure control of other metallic materials during LAM. | R.Wang J.Wang L.M.Lei S.Yu T.Hu S.S.Shuai S.Z.Xu Z.H.Cao X.P.Li C.Y.Chen Z.M.Ren | 2023 | Journal of Materials Science & Technology2023，，32： | 0 |
| 7 | On Temperature and Strain Rate Dependent Strain Localization Behavior in Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy显示文摘Deformation behaviors of Ti-6.5AI-3.5Mo- 1.5Zr-0.3Si alloys withα/βlamellar structure were investigated systematically at different temperatures from room temperature to 950℃and different strain rates.Results reveal that when the deformation temperature is higher than a critical temperature of 600℃,an evident transition of deformation behavior from localized shear banding toα/βlamella kinking,flow softening and temperature/strain rate-dependent peak flow stress occurred in the alloy.The critical conditions for the occurrence of internal cracking and strain localization behavior associated with temperature and strain rate were determined. | B.Zhang L.M.Lei X.L.Jiang Z.M.Song X.Huang G.P.Zhang | 2013 | Journal of Materials Science & Technology2013，29，3： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员