Prevention of Material Deterioration in ECM of Sintered Carbide with Iron Ions (2ndReport)

2017 ◽  
Vol 11 (5) ◽  
pp. 829-834
Author(s):  
Sicong Wang ◽  
Akihiro Goto ◽  
Atsushi Nakata ◽  
◽  

This study focuses on electrochemical machining as a method of processing sintered carbide at high speed. Previous studies have suggested the possibility of using electrochemical machining to achieve the high-speed machining of sintered carbide. However, there has been strong resistance from industry against bringing sintered carbide into contact with a conductive liquid. This is because the material quality of sintered carbide is degraded by the elution of Co when in contact with a conductive liquid. In previous reports, the authors have shown that it is possible to control the two modes of Co elution occurring during electrochemical machining: the elution from sintered carbide in contact with an electrolyte and the selective elution of Co arising from differences in the speeds of the dissolution of tungsten carbide and the elution of Co when sintered carbide is connected to an electrical source for processing. It is possible to control the elution of Co from sintered carbide in contact with an electrolyte by adding Co ions to the electrolyte, which increases the Co ion concentration. In addition, the excessive elution of Co can be prevented by using a bipolar electrical source for machining. Although we have shown that it is possible to carry out the electrochemical machining of sintered carbide without degrading its quality, the addition of large amounts of Co ions to the electrolyte is expensive. Therefore, we attempted to prevent the degradation in the quality of sintered carbide by adding iron ions instead of Co ions, and we confirmed that the addition of Fe ions has the desired effect. However, the Fe2+ions in the solution are easily oxidized to Fe3+ions with time, and the Fe3+ions yield no protective effect for sintered carbide. In our previous report, we discussed a method to bring the electrolyte into contact with Fe to prevent the oxidation of Fe2+ions to Fe3+ions and proposed the use of an iron filter. In the present report, we verify the effect of the iron filter.

2017 ◽  
Vol 11 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Akihiro Goto ◽  
◽  
Atsushi Nakata ◽  
Sicong Wang ◽  
Nagao Saito ◽  
...  

This study focuses on electrochemical machining as a method of processing sintered carbide at high speeds. Previous studies have suggested the possibility of using electrochemical machining to achieve high-speed machining of sintered carbide. However, there has been strong resistance in industry against bringing sintered carbide into contact with a conductive liquid. This is because the material quality of sintered carbide is degraded by the elution of Co when it is brought into contact with a conductive liquid.In previous reports, the authors have shown that it is possible to control two modes of Co elution occurring during electrochemical machining: the elution from sintered carbide when it comes into contact with an electrolyte, and the selective elution of Co due to difference in the speeds of WC dissolution and elution of Co when sintered carbide is connected to an electrical source for processing. It was shown that it is possible to control the elution Co in sintered carbide when it comes into contact with an electrolyte by adding Co ions to the electrolyte to increase the concentration of Co ion, and that it is possible to prevent the excessive elution of Co by using a bipolar electrical source for machining. Although we showed that it is possible to carry out electrochemical machining of sintered carbide without degrading its quality, adding of large amounts of Co ions to the electrolyte entails a high cost. In this report, therefore, we describe the addition of Fe ions instead of Co ions to perform electrochemical machining of sintered carbide without quality degradation.


2013 ◽  
Vol 581 ◽  
pp. 3-8
Author(s):  
Ján Duplák ◽  
Matúš Čuma ◽  
Miroslav Kormoš

The main part of Standard ISO 3685 is T-vc dependence for various cutting materials. The Standard ISO 3685 contains main properties and characteristics for three most important cutting materials those are used in engineering practice. These cutting materials are used for cutting tools made of high speed steel, cutting ceramic and sintered carbide. Some types of cutting materials are defined by means of descriptions in standards ISO, some types by means of catalogues from the manufacturer. There are a lot of types of cutting materials they have not been defined theirs properties exactly yet and theirs properties have to be defined on experiments. There is a presumption that descriptions in standards ISO are not correct and these standards have to be examined and verified, because that this fact have to be confirmed or disproved. Accuracy and completeness technical standards ISO are very important part quality of manufacturing. Article describes process how to define T-vc dependence for cutting tools made of high speed steel, cutting ceramic and sintered carbide, because were found deficiencies in valid standard ISO 3685.


2016 ◽  
Vol 10 (4s) ◽  
pp. 621-629
Author(s):  
Valentina Pidlisnyuk ◽  
◽  
John Harrington JR ◽  
Yulia Melnyk ◽  
Yuliya Vystavna ◽  
...  

The article focuses on examining the influence of fluctuations in annual precipitation amount on the quality of surface waters. Water quality was estimated with data on BOD, COD and phosphate–ion concentration within five selected regions of Ukraine. Analysis of the precipitation data (1991 – 2010) showed different regional trends. Using the statistics, determination of the interconnection between precipitation amount and water resources quality were done. The obtained regularities and associated uncertainties can be used for prediction of changes in water resource quality and as a guide for future adaptation to possible climate change.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Badusha M. ◽  
Santhosh S

The hydro geochemical features of Neyyar River for a period of one year from May 2015 to April 2016 were analyzed. Six sampling sites were fixed considering physiography and present landuse pattern of the river basin. The residents in the drainage basin are primarily responsible for framing a better landuse and thereby maintain a good water and sediment regime. Geospatial pattern of the present landuse of the study area indicated that the sustainability of this river ecosystem is in danger due to unscientific landuse practices, which is reflected in the river quality as well. The parameters such as hydrogen ion concentration, electrical conductivity, chloride, Biological Oxygen Demand, total hardness and sulphate of river water and Organic Carbon of river bed sediments were analyzed in this study. The overall analysis shows that the highland areas are characterized by better quality of water together with low organic carbon, which is mainly due to better landuse and minimal reclamation. The midland and lowland areas are characterized by poor quality of water with high organic carbon, which is due to high anthropogenic activities and maximum pollutants associated with the region together with the alteration in landuse from a traditional eco-friendly pattern to a severely polluted current pattern.


Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2667
Author(s):  
Kevin B. Comerford ◽  
Yanni Papanikolaou ◽  
Julie Miller Jones ◽  
Judith Rodriguez ◽  
Joanne Slavin ◽  
...  

Carbohydrate-containing crops provide the bulk of dietary energy worldwide. In addition to their various carbohydrate forms (sugars, starches, fibers) and ratios, these foods may also contain varying amounts and combinations of proteins, fats, vitamins, minerals, phytochemicals, prebiotics, and anti-nutritional factors that may impact diet quality and health. Currently, there is no standardized or unified way to assess the quality of carbohydrate foods for the overall purpose of improving diet quality and health outcomes, creating an urgent need for the development of metrics and tools to better define and classify high-quality carbohydrate foods. The present report is based on a series of expert panel meetings and a scoping review of the literature focused on carbohydrate quality indicators and metrics produced over the last 10 years. The report outlines various approaches to assessing food quality, and proposes next steps and principles for developing improved metrics for assessing carbohydrate food quality. The expert panel concluded that a composite metric based on nutrient profiling methods featuring inputs such as carbohydrate–fiber–sugar ratios, micronutrients, and/or food group classification could provide useful and informative measures for guiding researchers, policymakers, industry, and consumers towards a better understanding of carbohydrate food quality and overall healthier diets. The identification of higher quality carbohydrate foods could improve evidence-based public health policies and programming—such as the 2025–2030 Dietary Guidelines for Americans.


2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.


Author(s):  
Adel Abidi ◽  
Sahbi Ben Salem ◽  
Mohamed Athmane Yallese

Among advanced cutting methods, High Speed Milling (HSM) is often recommended to improve the productivity and to reduce the costs of machining parts. As every cutting process, HSM is characterized by some defects like surface roughness and delamination are the main defects generated in composite materials. The aim of this experimental work is the studying of the machining quality of woven Carbon fiber reinforced plastics (CFRP) using the HSM technology. Experiments were done using different machining parameters combinations to make opened holes in CFRP laminates. This study investigated the effect of cutting speed, orbital feed speed, hole diameter on the delamination defect and surface roughness responses generated in the drilled holes. The design of experimental tests was generated using the approach of Central Composite Design (CCD). The characterization of these responses was treated with the Analysis of variance (ANOVA) and Response surface methodology (RSM). Results showed that the surface roughness is highly affected by the orbital feed speed (F) with contribution of 22.45%. The delamination factor at entry and exit of holes is strongly influenced by the hole diameter D (25.97% and 57.43%) respectively. The developed model equations gave a good correlation between the empirical and predicted results. The optimization of the milling parameters was treated using desirability function to minimize the surface roughness (Ra) and the delamination factor simultaneously.


Author(s):  
Nguyen Duy Canh ◽  
Nguyen Van Canh ◽  
Pham Xuan Hong ◽  
Nguyen Ngoc Hue ◽  
Tran Dinh Duy

2013 ◽  
Vol 734-737 ◽  
pp. 1910-1914 ◽  
Author(s):  
Qiao Zhi Zhao ◽  
Qing You Yan

China is developing at relatively high speed, not only the regional development speed should be focused upon, but also the environmental impact of economic growth should be paid attention to, especially the level change of carbon dioxide emission. To some degree, quantity of carbon dioxide emission has become one of the most important indexes for measuring quality of a nations economic growth. Thus, this thesis is trying to analyze the driving relations between economic growth and carbon dioxide. Upon STIRPAT model, ridge regression method and elasticity theory are applied to analyze the influencing factors of carbon dioxide quantity such as the population quantity, Chinas urbanization process, per capita GDP, energy density and the percentage of the secondary industry. Correspondingly, based on the different influencing variables to carbon dioxide emission quantity, needy measures are brought out to control and decrease emissions. Feasible suggestions are trying to improve Chinas economic development quality.


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