Enhanced ductility and strength of Mg-1Zn-1Sn-0.3Y-0.2Ca alloy achieved by novel micro-texture design

2021 ◽  
Vol 204 ◽  
pp. 114119
Author(s):  
Cheng Wang ◽  
Hong Ning ◽  
Shi Liu ◽  
Jiang You ◽  
Tong Wang ◽  
...  
Keyword(s):  
2017 ◽  
Vol 36 (4) ◽  
pp. 1 ◽  
Author(s):  
Hugo Loi ◽  
Thomas Hurtut ◽  
Romain Vergne ◽  
Joelle Thollot
Keyword(s):  

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
C. I. Papadopoulos ◽  
L. Kaiktsis ◽  
M. Fillon

The paper presents a detailed computational study of flow patterns and performance indices in a dimpled parallel thrust bearing. The bearing consists of eight pads; the stator surface of each pad is partially textured with rectangular dimples, aiming at maximizing the load carrying capacity. The bearing tribological performance is characterized by means of computational fluid dynamics (CFD) simulations, based on the numerical solution of the Navier–Stokes and energy equations for incompressible flow. Realistic boundary conditions are implemented. The effects of operating conditions and texture design are studied for the case of isothermal flow. First, for a reference texture pattern, the effects of varying operating conditions, in particular minimum film thickness (thrust load), rotational speed and feeding oil pressure are investigated. Next, the effects of varying texture geometry characteristics, in particular texture zone circumferential/radial extent, dimple depth, and texture density on the bearing performance indices (load carrying capacity, friction torque, and friction coefficient) are studied, for a representative operating point. For the reference texture design, the effects of varying operating conditions are further investigated, by also taking into account thermal effects. In particular, adiabatic conditions and conjugate heat transfer at the bearing pad are considered. The results of the present study indicate that parallel thrust bearings textured by proper rectangular dimples are characterized by substantial load carrying capacity levels. Thermal effects may significantly reduce load capacity, especially in the range of high speeds and high loads. Based on the present results, favorable texture designs can be assessed.


2019 ◽  
Vol 55 (17) ◽  
pp. 85 ◽  
Author(s):  
ZHANG Hui ◽  
LIU Yang ◽  
WANG Wei ◽  
QIN Liguo ◽  
DONG Guangneng

Author(s):  
Young Woo Kwon ◽  
Mun Ki Bae ◽  
Ri-Ichi Murakami ◽  
Tae Hwan Jang ◽  
Tae Gyu Kim

In this study, a DLC pattern was fabricated through a photolithography process that constitutes a part of the semiconductor process, to investigate the frictional wear characteristics. The photolithography was used to produce negative patterns with a pattern width of 10 [Formula: see text]m or 20 [Formula: see text]m and a pattern depth of 500 nm on the DLC surface. The change in the coefficient of friction of the surface was investigated through a ball-on-disk tribology test on the fabricated micro/nano-sized DLC pattern. The DLC pattern fabricated by the photolithography process showed a superior coefficient of friction to that of the general DLC sample. These results show that the decrease in the surface friction coefficient of the patterned DLC thin film is due to the reduction in the surface contact area owing to the modification of the micro/nano-texture of the surface as well as the low friction characteristics of the DLC.


Author(s):  
Takahiro Funami ◽  
Sayaka Ishihara ◽  
Makoto Nakauma
Keyword(s):  

2019 ◽  
Vol 72 (5) ◽  
pp. 599-609
Author(s):  
Nilesh D. Hingawe ◽  
Skylab P. Bhore

Purpose The purpose of this study is to improve the tribological performance of meso scale air journal bearing by adopting texture on the bearing surface. Design/methodology/approach The present study is based on numerical analysis. The detailed numerical investigation is carried out using a fluid flow based thin-film model in COMSOL 5.2 software. Findings The influence of texture design parameters: geometry (shape, orientation and slender ratio), and position on the tribological performance of meso scale air journal bearing is investigated. It is found that texture shape has a strong influence on the tribological characteristics such as load capacity and friction coefficient of the bearing. Slender texture improves the load capacity, but it has a negligible effect on the reduction of friction coefficient. In contrast, texture orientation is found to be insignificant for both increasing load capacity and decreasing friction coefficient. Furthermore, the maximum improvement in load capacity is obtained for partially textured bearing, but the minimum friction coefficient is achieved for full texturing. Originality/value The present study investigates the influence of texture design parameters viz geometry (shape, orientation and slender ratio), and position on the tribological performance of meso scale air journal bearing.


2018 ◽  
Vol 274 ◽  
pp. 106-114 ◽  
Author(s):  
Feng Xue ◽  
Fan Wu ◽  
Jianwei Wang ◽  
Yue Hu

Nano Energy ◽  
2019 ◽  
Vol 58 ◽  
pp. 375-383 ◽  
Author(s):  
Tao Huang ◽  
Jing Zhang ◽  
Bin Yu ◽  
Hao Yu ◽  
Hairu Long ◽  
...  

Author(s):  
Zhenpeng He ◽  
Chun Zhang ◽  
Jianqiang Li ◽  
Yuanyuan Zhao ◽  
Aijun Sun

Accurate surface texture design is of great significance to improve the performances of gas bearings. In this article, the finite difference method and Newton’s method were combined to obtain the oil film pressure distribution, and the effect of rectangular groove on the lubrication performance was analyzed by changing representative texture parameters. The results show that the performances were more affected by the rectangular texture size compared with the distribution and the bottom shape of texture. The increasing of the surface texture number can only enhance the stability of the bearing. The bearing can provide 30% more bearing capacity by choosing larger size, radial arrangement and plane bottom. These results and analysis can provide technical reference for the bearing texture design.


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