Grinding Affect the Service Life of Mould Research

2013 ◽  
Vol 850-851 ◽  
pp. 225-228
Author(s):  
Fang He

In the process of modern mould manufacturing, grinding work still account for 25% ~ 45% of the total manufacturing time mould. Mould manufacturing quality of the finished product is closely related to the precision of mould manufacturing, particularly with the mould cavity surface accuracy and surface roughness has a close relationship. In the manufacturing of mould to make grinding micro cracks and residual stress is reduced to a minimum, full attention, grinding process in order to improve the service life of mould. So research to improve grinding processing quality, improve the service life of the mold, to extend the time of service, has the positive significance

2013 ◽  
Vol 709 ◽  
pp. 131-134
Author(s):  
Wei Xiang Liu ◽  
Zhong Yu Zhou

Residual stress produced on the surface of nanostructured ceramic coatings when they were grinded by diamond superhard abrasive wheel, these residual stresses affected directly the fracture strength, fatigue strength and corrosion resistance of the ceramic parts, they affected the surface quality of machined ceramic parts, and thus they affected the working reliability and the service life of ceramic parts. The tests show that the distribution of residual stress is directional, the residual compressive stress can make the hardness of the material increase, they can reduce the wear rate of the material, for the tested specimen, grinding surface whole residual stress σ is the sum up original residual stress σ0(existed in the part’s surface ) and grinding residual stress Δσ (formed by grinding process.), σ=σ0+ Δσ.


2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.


2010 ◽  
Vol 139-141 ◽  
pp. 269-273 ◽  
Author(s):  
Xiu Xu Zhao

Grinding is one of the important machining processes for the WC-Co carbide product. Different grinding strategies will have different impact on the work piece material. This study focuses on the WC-Co carbide grinding process, and the effect of grinding condition on the WC-Co carbide microstructure, figures out the relationship between different grinding strategies and material microstructure which relate to the WC-Co carbide tool failure. A specific microstructure analysis with Scanning Electric Microscope (SEM) will be presented based on a series of grinding experiments. The residual stress that generated in the grinding process will also be discussed based on the X-Ray Diffraction (XRD) measurements. It has been found that micro cracks are generated at certain grinding conditions with certain level. The residual stress which generated in the grinding process can be calculated by the d-spacing shift, and the comparison results show micro-cracks level is corresponding with the peaks shift in XRD test.


2016 ◽  
Vol 42 (5) ◽  
pp. 633
Author(s):  
Ping-Ping ZHANG ◽  
Hong-Xiang MA ◽  
Jin-Bao YAO ◽  
Miao-Ping ZHOU ◽  
Peng ZHANG

2021 ◽  
Vol 99 ◽  
pp. 103223
Author(s):  
Zhaojian Shi ◽  
Ling Liu ◽  
Kailong Zhang ◽  
Xiaolong Wang ◽  
Zhen Ma ◽  
...  
Keyword(s):  

2021 ◽  
Vol 1865 (2) ◽  
pp. 022004
Author(s):  
Chunyan Yang ◽  
Yun Hao ◽  
Yangping Li ◽  
Bozhe Wang ◽  
Hai Yuan ◽  
...  

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1057.2-1057
Author(s):  
Y. Liu ◽  
Y. Huang ◽  
Q. Huang ◽  
S. Sun ◽  
Z. Ji ◽  
...  

Background:Exosomes in synovial fluid (SF) has a close relationship with the pathogenesis of rheumatiod arthritis. As a complex biological fluid, SF presents challenges for exosomes isolation using standard methods, such as ExoquickTM kit and ultracentrifugation.Objectives:The study aims to compared the quality of exosomes separated by ExoquickTM kit (TM), ExoquickTM kit+ExoquickTC kit (TM-TC), ultracentrifugation (UC) and TM-TC+UC(TM-TC-UC) from SF.Methods:Exosomes was separated by TM, TM-TC, UC and TM-TC-UC respectively. The size and concentrations of exosomes were detected by high sensitivity flow cytometry for nanoparticle analysis. Total protein and RNA were extracted from exosomes. SDS-PAGE was used to detect the protein distribution of exosomes. Western blot was used to examine the level of albumin and exosomes marker (TSG101 and CD81).Results:There was no statistic difference in the diameters of exosomes separated by the four methods. The concentrations of exosomes in TM, TM-TC, TM-TC-UC and UC were (5.65±0.93), (3.02±1.19), (1.67±0.25) and (4.61±0.73) *109Particles/mL. The protein concentrations of exosomes separated by the four methods were consistent with the concentrations of exosomes. SDS-PAGE showed that the protein distribution of exosomes separated by the four methods were different. Low levels of albumin were detected in TM-TC and TM-TC-UC, while high levels of albumin in TM and UC. Total RNA concentrations from exosomes in TM-TC was higher than other groups.Conclusion:TM-TC can be used to obtain higher quality exosomes from SF for the study of exosome-enriched components.References:[1]Helwa I, et al, A Comparative Study of Serum Exosome Isolation Using Differential Ultracentrifugation and Three Commercial Reagents. PloS one, 2017. 12(1): p. e0170628-e0170628.Figure 1.A: SDS-PAGE showed the protein distribution of exosomes; B: the detection of albumin, TSG101 and CD81 by western blot.Disclosure of Interests:None declared


Author(s):  
Iwona Kowalczuk ◽  
Jerzy Gębski

The aim of the study was to examine whether, and to what extent, fear of contracting Covid-19 and compliance with the mandatory rules of isolation affected Polish adults’ nutritional behaviors. The online study was carried out during the first wave of the pandemic on a sample of 926 adults. Through cluster analysis, three groups of respondents were isolated: 1. People who fear a Covid-19 infection and follow the isolation rules (FFR), 2. People moderately afraid of the disease and following the rules loosely (MFFR), 3. People who are not afraid of the infection and do not follow the rules of isolation. (NFFR). The clusters were profiled with consideration of different aspects of eating behaviors as well as socio-demographic and economic features. The results of the study show a close relationship between the level of fear of contracting Covid-19 and the degree to which isolation rules are followed. These two factors were found to have a significant impact on eating behaviors, such as food purchases, eating patterns, and levels of consumption. It was stated that the FFR group changed their eating behaviors the most in terms of food purchasing, eating habits (excluding diversity and quality of diet), and food product consumption. The greatest stability in the majority of the analyzed areas of nutritional behaviors was observed in the MFFR cluster. The NFFR group shown the greatest decrease both in regularity and quality of their meals. This group also exhibited a significant increase in the consumption of alcoholic beverages. The results of the study can be useful in the decision making process when introducing restrictions or managing information. They also point to the need for extensive nutritional education focused on explaining the relationship between nutrition and health during a pandemic.


2013 ◽  
Vol 753-755 ◽  
pp. 277-280 ◽  
Author(s):  
Wei Xiang Liu

Nano-ceramic materials had high hardness and wear resistance. Combined with current technology and cost saving, nanostructured coatings technology were carried out, using HVOF ( high velocity oxygen fuel) or plasma spraying technique can obtain high quality ceramic coating on metal substrate. Ceramic coatings produced cracks in the grinding due to grinding surface residual stress. the coatings grinding surface residual stress of engineering ceramics have been researched, grinding surface residual stress in the nanostructured ceramic coatings are being researched. the researches in this field include grinding process modeling, abrasives and grinding parameters, grinding process monitoring and control and realization of the software, the grinding mechanism and grinding damage on the surface, grinding force prediction, on-line detection, grinding on nanocoating material is a multivariable complex process.


Author(s):  
Jacob Brink Jansson ◽  
Ruth Sørensen ◽  
Kirsten Riis

Cathodic protection is a very well-known method of preventing or stopping reinforcement corrosion and thereby extending the service life of reinforced concrete civil structures. However, a number of factors, which among others are design, materials and components, installation methods, quality of workmanship, and operation and maintenance of the cathodic protection system, have influence on the functionality and effectivity of the cathodic protection system. The optimum design that fulfils the Client''s requirements to cost, traffic disruption, service life, etc. shall be determined in accordance with the structure layout and the ability of the Client''s organisation to conduct operation and maintenance. It is critical to ensure that all components are installed properly to achieve the expected service life of the system. Regular and correct operation and maintenance is also crucial to ensure the functionality and effectivity system.


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