Experimental and numerical analysis of the wear mechanism in spring coil forming die and the effects of die geometry on wear

Author(s):  
Shuli Zhang ◽  
Decheng Wang ◽  
Peng Cheng ◽  
Chenxi Shao

The present work aimed at understanding the wear mechanism of spring coil forming die and the effects of die geometry on wear. The wear morphology was analyzed by scanning electron microscopy and energy dispersive spectrometer. The main wear mechanism was found to be adhesive wear, and a variant of the Archard wear model was established. The wear distribution in spring coil forming die was numerically analyzed in DEFORM software, and the effects of die geometry parameters on wear were discussed. Numerical results revealed that the wear distribution in the die was uneven and the wear mainly occurred at the sides of the die cavity. The wear depth was greatly affected by the width and angle of the die cavity, whereas the length of the die cavity had little effect. A small cavity width or angle led to severe wear, while a large cavity width reduced the forming quality of the spring coil. Moreover, a simple and effective life prediction method was proposed based on wear results. The findings of this research will be helpful for the effective design of spring coil forming die and the prediction of wear.

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 735
Author(s):  
Songchen Wang ◽  
Xianchen Yang ◽  
Xinmei Li ◽  
Cheng Chai ◽  
Gen Wang ◽  
...  

The objective of this study was to investigate the wear characteristics of the U-shaped rings of power connection fittings, and to construct a wear failure prediction model of U-shaped rings in strong wind environments. First, the wear evolution and failure mechanism of U-shaped rings with different wear loads were studied by using a swinging wear tester. Then, based on the Archard wear model, the U-shaped ring wear was dynamically simulated in ABAQUS, via the Umeshmotion subroutine. The results indicated that the wear load has an important effect on the wear of the U-shaped ring. As the wear load increases, the surface hardness decreases, while plastic deformation layers increase. Furthermore, the wear mechanism transforms from adhesive wear, slight abrasive wear, and slight oxidation wear, to serious adhesive wear, abrasive wear, and oxidation wear with the increase of wear load. As plastic flow progresses, the dislocation density in ferrite increases, leading to dislocation plugs and cementite fractures. The simulation results of wear depth were in good agreement with the test value of, with an error of 1.56%.


2021 ◽  
pp. 39-50
Author(s):  
Bo Peng ◽  
Xiao-Rui Ma ◽  
Wen-Ting Cui ◽  
Xia-Yu Tian ◽  
Chao Dong ◽  
...  

Soft rice is a kind of high-quality rice between glutinous rice and sticky rice. It has low amylose content, crystal clear grains, sweet taste, soft glutinous, and is suitable for cooking and porridge. Chalkiness in soft rice is a white opaque part formed by loose endosperm. It is an important character that affects the appearance quality, processing, and cooking quality of rice, and also an important limiting factor that restricts the standard rate of high-quality rice in China. The combination of scanning electron microscope and energy dispersive spectrometer (SEM-EDS) can be used for in-depth analysis of rice, visualization, and quantitative analysis of element distribution in rice. The results showed that there were many kinds of mineral elements in soft rice seeds, among which C and O were the most abundant, followed by N and P, and Mg, Al, P, S, K, Ca, Mn, and Zn were less. The contents of C, N, P, and S in the non-chalky area were significantly higher than those in the chalky area. Especially N and S were the best indicators of protein, and the contents in the chalky area were higher than those in the non-chalky area. It means that the protein content in the chalky part of soft rice seed is less than that in the non-chalky part, which affects the nutritional quality of soft rice. Therefore, the results of this study laid a solid foundation for the in-depth analysis of the distribution of mineral elements and protein in soft rice and their effects on the quality of soft rice, which also provided important information for the cultivation of new high-quality rice varieties in the future.


2011 ◽  
Vol 130-134 ◽  
pp. 1310-1313
Author(s):  
Yu Fu Xu ◽  
Wen Dong Li ◽  
Xian Guo Hu ◽  
Qiong Jie Wang

The corrosion behavior during friction of refined bio-oil by distillation process was evaluated by high frequency reciprocating test rig. Both scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) were used to investigate the morphology and active elements contents on the rubbed surface on steel disk. The chemical structures of the oils and the topography and surface roughness of the wear scar were also studied by FTIR and surface roughness tester as well, respectively. The experimental results showed that corrosion behavior of bio-oil was improved after refining since the wear depth was 3.75µm and the worn surface roughness was 0.172µm, while they were 12.5µm and 0.217µm before refining. It was concluded that corrosion degree of worn surface was decreased after the bio-oil was refined, which was ascribed to the decrease of the acidic component content after the refining process.


2021 ◽  
pp. 1-49
Author(s):  
Li Xiao ◽  
Yingqiang Xu ◽  
Zhiyong Chen

Abstract In this paper, a multi-layer body model in which material properties and wear coefficient change with node coordinates is proposed, so that the wear profile is not restricted by the singularity of the interface of the coated contact pairs. The conversion rate of the adhered particles was obtained to describe the growth and expansion of the debris at the fretting interface based on experiments, and the wear model of coated contact pair considering the dynamic evolution of the debris layer was established. By comparing the previous experimental and computational results, the wear calculation method proposed in this paper is more reasonable to predict the wear profile of the coated contact pair. In addition, the influence of the debris layer on the wear depth, friction width, and contact pressure in the fretting process is analyzed, indicating that the existence of the debris layer can delay the wear process. Finally, the fretting wear life of the SCMV steel contact pair deposited with the W-DLC coating is estimated.


2015 ◽  
Vol 7 (3) ◽  
pp. 78-92 ◽  
Author(s):  
Lilit Hakobyan ◽  
Jo Lumsden ◽  
Dympna O'Sullivan

Ongoing advances in mobile technologies have the potential to improve independence and quality of life of older adults by supporting the delivery of personalised and ubiquitous healthcare solutions. The authors are actively engaged in participatory, user-focused research to create a mobile assistive healthcare-related intervention for persons with age-related macular degeneration (AMD): the authors report here on our participatory research in which participatory design (PD) has been positively adopted and adapted for the design of our mobile assistive technology. The authors discuss their work as a case study in order to outline the practicalities and highlight the benefits of participatory research for the design of technology for (and importantly with) older adults. The authors argue it is largely impossible to achieve informed and effective design and development of healthcare-related technologies without employing participatory approaches, and outline recommendations for engaging in participatory design with older adults (with impairments) based on practical experience.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 638 ◽  
Author(s):  
Osama Asghar ◽  
Lou Li-Yan ◽  
Muhammad Yasir ◽  
Li Chang-Jiu ◽  
Li Cheng-Xin

Laser modification techniques have been widely adopted in the field of surface engineering. Among these modified techniques, ultra-high-speed laser cladding is trending most nowadays to fabricate wear-resistant surfaces. The main purpose of this research is to provide a detailed insight of ultra-high-speed laser cladding of hard Ni60 alloy on LA43M magnesium alloy to enhance its surface mechanical properties. Multiple processing parameters were investigated to obtain the optimal result. The synthesized coating was studied microstructurally by field emission scanning electron microscopy (FESEM) equipped with an energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The microhardness and wear resistance of the Ni60 coating were analyzed under Vickers hardness and pin on disc tribometer respectively. The obtained results show that the dense Ni60 coating was fabricated with a thickness of 300 μm. No cracks and porosities were detected in cross-sectional morphology. The Ni60 coating was mainly composed of γ-Ni and hard phases (chromium carbides and borides). The average microhardness of coating was recorded as 948 HV0.3, which is approximately eight times higher than that of the substrate. Meanwhile, the Ni60 coating exhibited better wear resistance than the substrate, which was validated upon the wear loss and wear mechanism. The wear loss recorded for the substrate was 6.5 times higher than that of the coating. The main wear mechanism in the Ni60 coating was adhesive while the substrate showed abrasive characteristics.


RSC Advances ◽  
2014 ◽  
Vol 4 (36) ◽  
pp. 19034-19042 ◽  
Author(s):  
Conglin Dong ◽  
Chengqing Yuan ◽  
Xiuqin Bai ◽  
Xinping Yan ◽  
Zhongxiao Peng

The main wear mechanism between the NBR pins and the 1Cr18Ni9Ti stainless steel rubbing pairs is severe adhesion tearing wear under the water-lubricated condition.


2019 ◽  
Vol 10 (1) ◽  
pp. 1-18
Author(s):  
Prince Semba Yawada ◽  
Mesmin J. Mbyamm Kiki ◽  
Mai Trung Dong

The effective design of a cognitive radio network must take into account economic and technical aspects. This article presents a commercial formulation of the spectrum by the primary operators who decide to sell a part of their spectrum to a group of cognitive users in order to earn money and to promote the efficient use of the spectrum. Three systems of spectrum pricing are compared and suggested, such as the cooperative price based on the optimization of the profits, the market equilibrium, and the competitive prices focused on the competition of Bertrand. The Bertrand model examines the influences of certain parameters of the system such as the quality of the channel based on the Nash equilibrium and the substitutability of the spectrum. The differences in the various aspects of these systems of pricing are presented through the graphs. The authors note through the obtained result that the profit of the primary operator depends not only on the demand quantity of the spectrum but also on the behavior of the primary operators.


2014 ◽  
Vol 14 (3) ◽  
pp. 141-149 ◽  
Author(s):  
Floyd Banda ◽  
Levy Siaminwe ◽  
Henry M. Mwenda

AbstractDrawn metal wires such as copper cables, aluminium wires and steel wires have found several applications which have an impact on the domestic and commercial economic uses, namely power cables, welding cables, wire ropes, wire meshes, electrode and filler wire, etc. All these applications require the use of good quality wires. However, this is not easily achieved since wire production faces many challenges. The influence of the drawing die on drawability and the need to maintain the required quality characteristics of the wire stand out among these challenges. This paper gives a background to wire drawing by highlighting the challenges of attaining the required drawability and quality characteristics during wire drawing. It was found from the literature that the draw die geometry has the greatest influence on the quality of copper, aluminium and steel wire products.


2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Gengxiang Wang ◽  
Hongzhao Liu

Effects of wear and member flexibility on the dynamic performance of a planar five-bar mechanism with joint-clearance are investigated. The equation of motion of the mechanism is derived based on the absolute nodal coordinate formulation (ANCF). In order to enhance the accuracy of the contact force, the slope of the load–displacement curve of the cylindrical joint with clearance is used. The contact deformation couples the joint wear to the contact state. The contact force model of Flores and coworkers is improved, by the introduction of the stiffness coefficient. The wear depth is predicted by using the Archard's wear model. Simulations show that the multiclearance joints can generate stronger contact forces relative to single clearance joint case. This leads to more severe wear in the joint. However, the mechanism with multiple flexible links can absorb more of the energy arising from the clearance joint, and this improves the wear phenomenon.


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