|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Weldability, microstructure and mechanical properties of laser-welded selective laser melted 304 stainless steel joints显示文摘Laser welding is a promising process for joining small components produced by selective laser melting (SLM) to fabricate the large-scale and complex-shaped parts. In the work, the morphology, microstructure, microhardness, tensile properties and corrosion resistance of the laser welded stress-relieved SLMed 304 stainless steel joints are investigated, as the different sections of stress-relieved SLMed 304 stainless steel are joined. Results show that the SLMed 304 stainless steel plates have a good laser weldability. The microstructure of laser-welded joints consists of the cellular dendrites in austenite matrix within columnar grains, exhibiting a coarser dendrite structure, lower microhardness (~220HV) and tensile properties (tensile strength of ~750 MPa, and area reduction of ~27.6%), but superior corrosion resistance to those of SLMed plates. The dendrite arm spacing of the joints varies from ~3.7μm in center zone, to ~5.0 (xm in fusion zone, to ~2.5 in epitaxial zone. The SLMed anisotropy shows a negligible effect on the microstructure and performance of the laser-welded joints. The laser welding along the building directions of the SLMed base plates can induce a slightly finer dendritic structure and higher tensile properties. | Jingjing Yang Yun Wang Fangzhi Li Wenpu Huang Guanyi Jing Zemin Wang Xiaoyan Zeng | 2019 | Journal of Materials Science & Technology2019，35，9： | 14 |
| 2 | Microstructural evolution and mechanical properties of 300M steel produced by low and high power selective laser melting显示文摘300 M ultra-high strength steel has been widely used in critical structural components for aviation and aerospace vehicles,owing to its high strength,excellent transverse plasticity,fracture toughness and fatigue resistance.Herein,low and high power selective laser melting(SLM)of 300 M steel and their microstructural evolution and mechanical properties have been reported.The results show that the optimal energy density range with the highest relative density for SLMed 300 M steel is between 60 and160 J/mm^3.Furthermore,molten pools for deposition exhibit a conduction mode with semi-elliptical shape at a lower laser power of 300~600 W but a keyhole mode with'U'shape at a higher laser power of 800~1900 W.The heterogeneous microstructure of as-built samples is cha racterized by a skin-core structure which is that tempered troostite with the coarse non-equiaxed grains in the molten pool is wrapped by tempered sorbite with the fine equiaxed grains in the heat-affected zone.The skin-core structure of SLMed 300 M steel has the characteristics of hard inside and soft outside.The average microhardness of samples varies from 385 to 341 HV when laser power increases from 300 to 1900 W.Interestingly,ultimate tensile strength(1156-1193 MPa)and yield tensile strength(1085-1145 MPa)of dense samples fabricated at diffe rent laser powers vary marginally.But,the elongation(6.8-9.1%)of SLMed 300 M steel is greatly affected by the laser power. | Guanyi Jing Wenpu Huang Huihui Yang Zemin Wang | 2020 | Journal of Materials Science & Technology2020，47，13： | 5 |
| 3 | Effects of circular beam oscillation technique on formability and solidification behaviour of selective laser melted Inconel 718:From single tracks to cuboid samples显示文摘The inherent drawbacks of selective laser melting technique including serious micro-pore and element microsegregation problems destroy the mechanical property of the component.To overcome this problem,a new approach,circular beam oscillation,was successfully applied in the SLMed Inconel 718 samples including single tracks,thin walls and cuboid samples.On one hand,circular beam oscillation reduces the micro-pores in molten pools and cuboid samples,increasing the relative density of the cuboid sample to 99.95%.On the other hand,circular beam oscillation suppresses the element microsegregation,reducing the formation of Laves phases in SLMed Inconel 718 samples.Moreover,circular beam oscillation enhances the<001>texture of thin walls and the<101>texture of cuboid samples.The improvement of formability and microstructure of the SLMed samples with oscillation is closely related to cooling rate,thermal gradient and stirring effect during the solidification process.Therefore,circular beam oscillation shows the possibility to overcome the key bottlenecks of the traditional SLM technology and to realize a further industrial application of SLM technology. | Huihui Yang Guanyi Jing Piao Gao Zemin Wang Xiangyou Li | 2020 | Journal of Materials Science & Technology2020，47，16： | 2 |
| 4 | Controllable in-situ aging during selective laser melting: Stepwise precipitation of multiple strengthening phases in Inconel 718 alloy显示文摘controllable in-situ aging treatment of Inconel 718 alloy was successfully developed by governing the types and times of the thermal cycles during selective laser melting (SLM). The sequential precipitation of γ' composite phase of primary/secondary y ' coated by a γ″shell, and γ″ occurs as the times of vertical thermal cycles increase when laser peak temperature (Ip) is between the precipitation temperature of strengthening phase {TpTe) and liquid temperature (7l ), which causes an increase in microhardness by 4 0 HV. Also, short-term aging mechanisms on three types of strengthening phases are proposed based on a great number of vacancies in the matrix. | Huihui Yang Jingjing Yang Wenpu Huang Guanyi Jing Zemin Wang Xiaoyan Zeng | 2019 | Journal of Materials Science & Technology2019，35，9： | 1 |
| 5 | Research on positioning enhancement scheme of CAPS via UWB pseudolite显示文摘The positioning precision of the transmitting Chinese Area Positioning System(CAPS) is reduced due to the non-ideal distribution of the satellite constellation.Positioning and navigation enhancement methods are able to improve the reliability and accuracy of the positioning system,especially for users in special regions and special applications.In this paper,a positioning enhanced scheme based on ultra-wide band(UWB) pseudolite is proposed for CAPS.It is demonstrated that the link budget of UWB pseudolite satisfies the FCC's emission mask requirements.The localization algorithm of the enhanced CAPS is presented.The simulations indicate that the positioning precision of the proposed enhanced scheme is improved greatly,and the feasibility of the enhanced scheme is thus proved. | XIAO Zhu BAI Jing MA GuanYi FAN JiangTao YI KeChu | 2012 | Science China(Physics,Mechanics & Astronomy)2012，55，4： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员