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Journal of Materials Science & Technology 2022年第2期97卷 101-112页

作者： Yang Liu Samuel C.V.Lim Chen Ding Aijun Huang Matthew Weyland Department of Materials Science and Engineering Monash UniversityClaytonVIC3800Australia Monash Centre for Additive Manufacturing Monash UniversityNotting HillVIC3168Australia BAOWU Special Metallurgy Co.Ltd. Shanghai200940China Monash Centre for Electron Microscopy Monash UniversityClaytonVIC3800Australia

The competitive effect of microstructural features including primaryα(α_(p)),secondaryα(α_(s)),grain boundaryα(α_(GB)) and β grain size on mechanical properties of a near β Ti alloy were studied with two heat treatment *** relative effect of β grain size and STA(solution treatment and ageing)processing parameters on mechanical properties were quantitatively explored by the application of Taguchi *** results were further explained via correlating microstructure with the fracture toughness and tensile *** was found that large numbers of fine as precipitates and continuous α_(s) played greater roles than other features,resulting in a high strength and very low ductility(features and the overall sum of their effect on fracture toughness and tensile properties.A novel table was proposed to quasi-quantitatively unravel these competitive effects.

关键词： Nearβtitanium alloys microstructural features Competitive effect Fracture toughness βgrain size effect

Effect of Sn Content on the microstructural features, Martensitic Transformation and Mechanical Properties in Ti-V-Al-Based Shape Memory Alloys

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Acta Metallurgica Sinica(English Letters) 2023年第8期36卷 1247-1260页

作者： Xiao-Yang Yi Wei Liu Yun-Fei Wang Bo-Wen Huang Xin-Jian Cao Kui-Shan Sun Xiao Liu Xiang-Long Meng Zhi-Yong Gao Hai-Zhen Wang Department of Nuclear Equipment College of Nuclear Equipment and Nuclear EngineeringYantai UniversityYantai264005China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai264005China

In the present study, it is expected to tailor the microstructural features, martensitic transformation temperatures and mechanical properties of Ti-V-Al shape memory alloys through adding Sn alloying elements, which further expands their applications. Sn addition results in the monotonous rising of average valence electron number (e/a). In proportion, the single α″ martensite phase directly evolves into merely β parent phase in present Ti-V-Al-based shape memory alloys, as Sn content increases from 0.5 to 5.0 at.%. Meanwhile, Sn addition causes the reduction in the grain size. Combined with transmission electron microscopy (TEM) observation and d electron theory analysis, it can be speculated that Sn addition can suppress the precipitation of ω phase. With increasing Sn content, fracture strength invariably decreases from 962 to 792 MPa, whereas the yield strength firstly decreases and then increases. The lowest yield stress for the stress-induced martensitic transformation of 220 MPa can be obtained in Ti-V-Al shape memory alloy by adding 3.0 at.% Sn. By optimizing 1.0 at.% Sn, the excellent ductility with a largest elongation of 42.1% can be gained in Ti-V-Al shape memory alloy, which is larger than that of the reported Ti-V-Al-based shape memory alloys. Besides, as a result of solution strengthening and grain refinement, Ti-V-Al-based shape memory alloy with 5.0 at.% Sn possesses the highest yield strength, further contributing to the excellent strain recovery characteristics with 4% fully recoverable strain.

关键词： Ti-V-Al alloy Lightweight shape memory alloy microstructural features Mechanical properties strain recoverycharacteristics

Influence of different microstructural features on impact toughness and crack initiation behavior of coarse grain heat-affected zone in X80 pipeline steel

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Baosteel Technical Research 2021年第4期15卷 2-11页

作者： QIAN Weifang Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai 201999China

Coarse grain heat-affected zone samples of X80 pipeline steel under different heat inputs were obtained through thermal welding simulation experiments with Gleeble *** impact tests and a combination of multiscale characterizations were conducted to investigate the influence of various microstructural features on impact toughness and crack initiation *** results prove that, as the heat input increases, the number of M/A components increases, thereby degrading toughness and increasing ***, more M/A constituents tend to aggregate on prior austenite grain boundaries(PAGBs),and the overall dimensions of M/A and the width and volume fraction of the lath martensite substructure inside M/A islands would increase as *** changes make intersections between boundary M/As and PAGBs become one of the preferred sites for crack *** addition, only large-sized grotesque inclusions can act as a direct inducement of crack initiation.

关键词： X80 pipeline steel coarse grain heat-affected zone microstructural features impact toughness crack initiation

Quantification and Statistical Analysis of microstructural features in As-cast Ti-6Al-4V Titanium Alloy

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Quantification and Statistical Analysis of Microstructural F...

Microstructure and properties of Cu-Ni-Si-Zr alloy after thermomechanical treatments

中国材料大会2012

作者： Xiangjun Cheng Guoqing Wu Jiaqi Zhao School of Mat. Sci. & Eng. Beihang University Beijing institute of Aeronautical Materials

ISBN: (纸本)9783037856086;3037856084

Based on microstructure of as-cast Ti-6Al-4V titanium alloy, an image processing to simplify model of β grain size, α lamella space was developed and a quantitative statistical method of β grain size, α lamella space in two-phase titaniumalloys wasestablished,with which β grain size and α lamella space of as-cast Ti-6Al-4V titanium alloy with different plate thickness were analyzed. The relationship between β grain size, α lamellar space and cast plate thickness was discussed. The results show that β grain size and α lamellae thickness nearly linearly increase as plate thickness increasing. β grain size has normal distribution and with cast plate thickness increasing, the dispersion gets larger.

关键词： Titanium alloy microstructural features Quantitative analysis Statistical analysis.

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Rare Metals 2013年第2期32卷 144-149页

作者： Xiang-Peng Xiao Bai-Qing Xiong Qiang-Song Wang Guo-Liang Xie Li-Jun Peng Guo-Xing Huang State Key Laboratory for Fabrication and Processing of Non-ferrous Metals General Research Institute for Nonferrous Metals Aluminum Corporation of China Limited Luoyang Copper Co. Ltd.

The effect of thermomechanical treatments on the microstructures and properties of Cu-2.1Ni-0.5Si- 0.2Zr alloy was investigated. The hot-rolled plates were solution treated at 920 ℃ for 1.5 h, quenched into water, cold rolled by 70 % reduction in thickness, and then aged at 400, 450 and 500 ℃for various times. The variation in tensile strength and electrical conductivity of the alloy was measured as a function of the aging time. The results show the peak strength value of 665 MPa for the alloy aged at 450 ℃ for 2 h. However, the electrical conductivity is observed to reach a maximum of 47 % IACS aged at 450℃for 8 h. OM, SEM, and TEM were used for microstructural inspection of the alloy. Precipitation occurs preferentially at deformation bands in the cold-rolled alloy. Properties behavior is discussed in the light of microstructural features.

关键词： Cu-Ni-Si-Zr alloy Precipitation Electricalconductivity Tensile strength microstructural features

Micropillar compression using discrete dislocation dynamics and machine learning

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 39-47页

作者： Jin Tao Dean Wei Junshi Yu Qianhua Kan Guozheng Kang Xu Zhang School of Mechanics and Aerospace Engineering Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

Discrete dislocation dynamics(DDD)simulations reveal the evolution of dislocation structures and the interaction of *** study investigated the compression behavior of single-crystal copper micropillars using fewshot machine learning with data provided by DDD *** types of features are considered:external features comprising specimen size and loading orientation and internal features involving dislocation source length,Schmid factor,the orientation of the most easily activated dislocations and their distance from the free *** yielding stress and stress-strain curves of single-crystal copper micropillar are predicted well by incorporating both external and internal features of the sample as separate or combined *** is found that the machine learning accuracy predictions for single-crystal micropillar compression can be improved by incorporating easily activated dislocation features with external ***,the effect of easily activated dislocation on yielding is less important compared to the effects of specimen size and Schmid factor which includes information of orientation but becomes more evident in small-sized ***,incorporating internal features,especially the information of most easily activated dislocations,improves predictive capabilities across diverse sample sizes and orientations.

关键词： Discrete dislocation dynamics simulations Machine learning Size effects Orientation effects microstructural features

Influence of Non-Natural Ageing Temperature on the microstructural Characteristics and Mechanical Properties of Cast Aluminum 6063 Alloy

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Journal of Minerals and Materials Characterization and Engineering 2024年第2期12卷 91-99页

作者： Oluwole Oladele Ayodele Adedeke Olajesu Olanrewaju Samuel Olusunle Department of Metallurgical and Materials Engineering Federal University of Technology Akure Ondo State Nigeria Engineering Materials Development Institute NASENI Akure Ondo State Nigeria Department of Materials Science and Engineering Iowa State University Ames IA USA NASENI Abuja Nigeria

This research considered the effect of non-natural aging on the microstructural characteristics and mechanical properties of as-cast aluminum 6063 alloys. The samples were developed through a sand casting process and machined into tensile and impact test samples before carrying out solution heat treatment at 550?C (0.83 Tm) on two parts of the samples while retaining one part as the control. The two parts were further divided into sets denoted A and B and were aged at 180?C (0.27 Tm) and 160?C (0.24 Tm), respectively, for 12 hours. The results showed that sample A has the optimal yield strength and ultimate tensile strength of 192 and 206 MPa, respectively. Likewise, the sample gave the highest impact strength value of about 9.63 J/mm2. The observed results were supported by the optical micrograph, which revealed that the sample has evenly dispersed precipitates in its microstructure. This is deemed responsible for the observed increase in strength of the sample.

关键词： Aluminum Alloy Non-Natural Ageing Mechanical Properties microstructural features

Insightful Understanding of the Role of the Mechanical Properties in Defining the Reliability of All-Ceramic Dental Restorations: A Review

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Journal of Biomaterials and Nanobiotechnology 2021年第4期12卷 57-78页

作者： Mohammad Albakry Department of Restorative Dental Sciences Faculty of Dentistry University of Najran Najran KSA

Since the last two decades, restorative dentistry has been witnessing an increased acceptance of the use of the well-known all-ceramic materials for the fabrication of single dental restorations, such as inlays, onlays, crowns, anterior and posterior fixed partial dentures (PFPDs). These restorations certainly offer the potential for better biocompatibility coupled with superior aesthetic qualities, especially when compared with the conventional prostheses made from porcelain that is fused with metal ceramic restorations. However, brittleness and extreme sensitivity of all-ceramic materials to micro-like defects or cracks that are inherently present, or may grow, in their microstructure during different laboratory fabrication steps, during necessary clinical adjustments, or from post-placement chewing activity, remain major shortcomings of these dental restorations. In fact, many researchers are of the opinion that the improved mechanical properties can significantly improve the lifetime of all-ceramic restorations and result in enhanced reliability. Therefore, efforts of researchers, as well as manufacturers, have been directed towards the improvement of the mechanical properties in order to overcome such limitations. This article reviews the characterization of the most important mechanical properties that can delineate the behavior of all-ceramic dental materials upon loading. These include fracture mechanics, the brittle nature of ceramics, the relationship between microstructural features and fracture behavior, sources of cracks and flaws that may initiate a fracture and the effect of different fabrication procedures and/or clinical adjustments on the mechanical behavior of dental ceramics are also reviewed and discussed.

关键词： Mechanical Properties Fracture Mechanics All-Ceramic Dental Restorations microstructural features Microcracks