Search

Your search keyword '"Lu, Guoxin"' showing total 131 results
Start Over Author "Lu, Guoxin"
131 results on '"Lu, Guoxin"'

23. Research Progress of Laser Shock Treatment in the Field of Material Forming

Author

YANG Fenghuai, LU Guoxin, YANG Qingtian, and ZHANG Yongkang

Subjects
laser shock, material forming, surface strengthening, numerical simulation, Motor vehicles. Aeronautics. Astronautics, TL1-4050
Abstract

Laser shock treatment is a kind of advanced surface strengthening technology for metallic materials, and its remarkable strengthening effect has been verified and universally accepted in many different metallic materials. In order to prevent the influence of laser shock on the shape size of precision parts or make use of the technology to introduce plastic deformation of metallic materials, it is necessary to study the deformation criterion of materials under laser shock. In this paper, the deformation law of different materials treated by laser shock is analyzed, and the limitation of laser shock in deformation phenomenon is explained based on the deformation mechanism of stress gradient and impact bending, the necessity of basic research on material deformation caused by laser shock is proposed. The effect of many factors such as laser parameters and impact modes, constraint modes on the laser shock-induced deformation is summarized, and it is proved that the adjustment and optimization of multiple parameters play an important role in controlling laser shock-induced deformation degree. Moreover, the advantages of numerical simulation method in the study of laser shock-induced deformation are analyzed in this paper, and at the same time,the urgency of establishing a material constitutive model adapting to high strain rate deformation and perfecting the simulation of laser plasma formation process is put forward. The development of laser shock deformation law in advanced manufacturing industry is prospected through the introduction of the sizing technology of laser shock, and the research directions of the deformation calibration based on laser shock and the on-line monitoring of deformation degree are presented.

Published
2018
Full Text
View/download PDF

27. Effect of Twice Hole Expansion on Fatigue Property of Ti1023 Alloy

Author

YANG Guangyong, LI Meng, SONG Yinggang, LU Guoxin, and HUANG Lijun

Subjects
hole expansion, fretting wear fatigue, residual stress, fatigue property, Motor vehicles. Aeronautics. Astronautics, TL1-4050
Abstract

The property of the surface layer of twice hole expansion Ti1023 alloy was analyzed by TEM, X-ray and roughness tester, and the strengthen mechanism of the bushing hole expansion was discussed. The results indicate that the roughness(Ra1.722→0.349 μm), hardness(Hv32→38) and residual stress distribution of the hole are improved by twice hole expansion techniques,and the fretting wear fatigue(fatigue limits 385→619MPa) of Ti1023 alloy is improved.

Published
2016
Full Text
View/download PDF

32. A study on forming limit diagram and laminated stamping of paperboard.

Author

Gao, Ying, Li, Yajie, Ji, Zhong, Zhang, Cunsheng, Lu, Guoxin, and Liu, Ren

Subjects
CARDBOARD, LAMINATED materials, HYGIENE
Abstract

Coated paperboard not only has the advantages of traditional paper such as low density and cleanliness, but also overcomes its disadvantages such as poor barrier performance and sensitivity to moisture. It is more and more widely used in forming packaging containers. The current research on mechanical performance and inelastic deformation of paperboard mainly focus on its physical properties and simplified single-blank forming, but the studies on the forming limit diagram (FLD) of paperboard are relatively rare. In this paper, Nakajima tests have been carried out to determine the FLD curves of the polyethylene-coated paperboard blank along the machine direction, cross direction, and diagonal direction. A laminated stamping method for multi-blank is proposed and investigated by experiment and numerical simulation. Up to 5 blanks can be overlapped and stamped in a single punch stroke, and 5 bowl-shaped packaging containers can be formed simultaneously. Compared with the single-blank stamping process, the production efficiency can be greatly improved, but the flange area of the forming parts is easier to wrinkle. However, the wrinkling risk can still be controlled by optimizing the process parameters, such as friction factor and blank holder gap. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

45. Effect of stress-relief heat treatment on the stress-rupture properties of a nickel-based superalloy manufactured by laser powder bed fusion

Author

Zhang, Weiguang, Gao, Shuang, Song, Zhenfeng, Li, Shuijin, Lan, Liang, Hou, Jieshan, Lu, Guoxin, and He, Bo

Abstract

Residual stress is a ubiquitous phenomenon in laser powder bed fusion (LPBF) metal parts due to high temperature gradients and uneven heating during building processes. Subsequent stress-relief (SR) heat treatment is usually conducted to reduce the geometrical distortion and microscopic cracks induced by residual stress after the LPBF process. Using electron microscopy, X-ray diffraction, and stress-rupture tests, the experimental results revealed that the stress-rupture life of a nickel-based superalloy, IN625 alloy, subjected to SR treatment at 870°C and 980°C is inferior to that of the as-built (AB) alloy. The fundamental cause for this phenomenon is that more δ phase precipitates in the grains of the AB alloy during the stress-rupture test at 750°C/230 MPa, resulting in an increased dispersion hardening effect and a decreased ductility. Furthermore, the Laves and δ phases along grain boundaries in the SR treated alloys are more likely to coarsen, which is the second reason for the decreased stress-rupture life of the SR treated alloys.

Published
2024
Full Text
View/download PDF

46. Interfacial self-transportation viacontrolled wettability transition for directed self-assembly

Author

Tian, Pan, Tan, Minghui, Zhu, Guiqiang, Wang, Dan, Lu, Guoxin, and Cheng, Mengjiao

Abstract

Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems. The broad-spectrum responsiveness of the wettability transition makes it a promising way to expand innovative applications. Here, we develop a track-guided self-transportation system mediated by sequential wettability transition accompanied with capillary transportation. Alkaline fuel is loaded into polydimethylsiloxane (PDMS) cuboid to trigger the wettability transition of distributed superhydrophobic tracks laid in shallow water. After the wettability transition, the induced capillary force can propel the repetitive track-to-track transportation of PDMS. Importantly, the spacing between adjacent tracks is rationally designed based on multiple factors including threshold of wettability transition, diffusion kinetics and capillary interaction. Furthermore, the track-guided transportation system is applied to realize directed self-assembly of multiple PDMS building blocks for designated configuration, which increases the complexity and intelligence of self-assembly systems.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results