scholarly journals Process Parameter Impact on Suspension-HVOF-Sprayed Cr2O3 Coatings

2019 ◽  
Vol 28 (8) ◽  
pp. 1933-1944 ◽  
Author(s):  
Jarkko Kiilakoski ◽  
Richard Trache ◽  
Stefan Björklund ◽  
Shrikant Joshi ◽  
Petri Vuoristo

Abstract Chromium oxide (Cr2O3) is commonly used as an atmospheric plasma-sprayed (APS) coating from powder feedstock in applications requiring resistance to sliding wear and corrosion, as well as amenability to texturing, e.g., in anilox rolls. Recently, high-velocity oxy-fuel spray methods involving suspension feedstock have been considered an extremely promising alternative to produce denser and more homogeneous chromium oxide coatings with lower as-sprayed surface roughness, higher hardness and potentially superior wear performance compared to conventional APS-sprayed coatings. In this study, the impact of process parameters namely auxiliary air cleaning nozzles and a transverse air curtain on suspension high-velocity oxy-fuel-sprayed Cr2O3 suspensions is presented. The produced coatings are characterized for their microstructure, mechanical properties and wear resistance by cavitation erosion. The results reveal the importance of optimized air nozzles and air curtain to achieve a vastly improved coating structure and performance.

2016 ◽  
Vol 254 ◽  
pp. 71-76 ◽  
Author(s):  
Norbert Kazamer ◽  
Dragos Toader Pascal ◽  
Gabriela Marginean ◽  
Viorel Aurel Şerban ◽  
Cosmin Codrean ◽  
...  

In order to be competitive, it is demanded to have thin, tough and long lasting coatings. An important aspect is to use stable deposition technologies. As Cr assures wear, corrosion and high temperature resistance, the most employed coatings in industry generally contain Cr. Nevertheless, Cr is a hazardous element for the humans’ health, therefore, sustainable alternatives are needed to be implemented. The aim of this work is to investigate the microstructure, hardness, corrosion resistance and wear behavior of the novel WC-CoMo compared to conventional WC-Co coatings. So far, WC-CoMo coatings are not part of state of the art regarding the Atmospheric Plasma Sprayed (APS) coatings. WC-Co powder in plain form and mechanically mixed with Mo was deposited using the APS method on standardized Type A Almen Strips (C67 steel). The size of the powder grains varies between 5 µm and 30 µm. The obtained samples were investigated by means of Scanning Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, X-Ray Diffraction, and hardness, wear and corrosion behavior were also evaluated. Results revealed formation of different intermetallic phases around the WC particles, which have a benefic influence on the coating characteristics and microstructure.


2020 ◽  
Author(s):  
Yidong Jiang ◽  
Wenfei Mo ◽  
Tianyu Cao ◽  
Yixiang Shi ◽  
Ningsheng Cai

Abstract A Solid oxide fuel cell (SOFC) with a liquid antimony anode (LAA) is a potential energy conversion technology for impurity-containing fuels. Atmospheric plasma spraying (APS) technology has become a promising LAA-SOFC preparation method because of its economy and convenience. In this paper, button SOFCs with different cathode materials and ratios of pore former were prepared by the APS method and measured at 750°C. The effect of the cathode structure on the electrochemical performance of the LAA-SOFCs was analyzed, and an optimized spraying method for LAA-SOFCs was developed. A tubular LAA-SOFC was prepared by the APS method based on the optimized spraying method and a peak power of 2.5 W was reached. The tubular cell was also measured at a constant current of 2 A for 20 hours and fed with a sulfur-containing fuel to demonstrate its impurity resistance and electrode stability.


Author(s):  
Yidong Jiang ◽  
Wenfei Mo ◽  
Tianyu Cao ◽  
Yixiang Shi ◽  
Ningsheng Cai

AbstractA solid oxide fuel cell (SOFC) with a liquid antimony anode (LAA) is a potential energy conversion technology for the use of impurity-containing fuels. Atmospheric plasma spraying (APS) technology has become a promising LAA-SOFC preparation method because of its economy and convenience. In this paper, button SOFCs with different cathode materials and ratios of pore former were prepared by the APS method and were operated at 750 °C. The effect of the cathode structure on the electrochemical performance of the LAA-SOFCs was analyzed, and an optimized spraying method for LAA-SOFCs was developed. A tubular LAA-SOFC was prepared using the APS method based on the optimized spraying method, and a peak power of 2.5 W was reached. The tubular cell was also measured at a constant current of 2 A for 20 h and was fed with a sulfur-containing fuel to demonstrate its impurity resistance and electrode stability.


2005 ◽  
pp. 53-68 ◽  
Author(s):  
R. Kapeliushnikov ◽  
N. Demina

The paper provides new survey evidence on effects of concentrated ownership upon investment and performance in Russian industrial enterprises. Authors trace major changes in their ownership profile, assess pace of post-privatization redistribution of shareholdings and provide evidence on ownership concentration in the Russian industry. The major econometric findings are that the first largest shareholding is negatively associated with the firm’s investment and performance but surprisingly the second largest shareholding is positively associated with them. Moreover, these relationships do not depend on identity of majority shareholders. These results are consistent with the assumption that the entrenched controlling owners are engaged in extracting "control premium" but sizable shareholdings accumulated by other blockholders may put brakes on their expropriating behavior and thus be conductive for efficiency enhancing. The most interesting topic for further more detailed analysis is formation, stability and roles of coalitions of large blockholders in the corporate sector of post-socialist countries.


2019 ◽  
Vol 10 (2) ◽  
pp. 144-151
Author(s):  
Noora Ahmed Lari ◽  

The State of Qatar has implemented several family policies in order to improve the wellbeing of Qatari families and ensure fair distribution of development benefits for both men and women. However, there is a linkage between female employment outside the home and instability in the marriages of Qatari families. This paper investigates the impact of female employment on marital stability, based on the results of primary data collected in Qatar, a questionnaire that consisted of several sections such as challenges in the workplace, supervisor, family and spouse relations, work motivation and performance. Of the 824 questionnaires that were returned, 807 were completed and valid for analysis. Regression analysis and an ANOVA test have been used to test the relationship between the variables. The results of the research have produced mixed findings about how wives’ employment increases marital instability and have yielded few significant differences on mean scores of discuss on work demands, insufficient time together, housework, financial matters, communication, relatives and rearing children. The results indicates that in general Qatar working women face several challenges in relation to their marital life as part of cultural and social constraints.


2018 ◽  
Vol 12 (2) ◽  
pp. 60-63
Author(s):  
Mariana Sandu ◽  
Stefan Mantea

Abstract Agri-food systems include branching ramifications, which connect in the upstream the input suppliers with farmers, and downstream farmers, processors, retailers and consumers. In the last decades, at the level of the regions, food systems have undergone rapid transformation as a result of technological progress. The paper analyzes the changes made to the structure, behavior and performance of the agri-food system and the impact on farmers and consumers. Also, the role of agricultural research as a determinant factor of transformation of agri-food system is analyzed. The research objective is to develop technologies that cover the entire food chain (from farm to fork) and meet the specific requirements of consumers (from fork to farm) through scientific solutions in line with the principles of sustainable agriculture and ensuring the safety and food safety of the population.


2020 ◽  
Vol 26 (2) ◽  
pp. 299-315
Author(s):  
V.V. Smirnov

Subject. The article discusses the momentum in finance. Objectives. The study reveals the impact of financial momentum as the unity of antipodes in the development of the national economy. Methods. The study is based on a systems approach and methods of descriptive statistics. Results. I discover the ultimate goal of globalization, i.e. the substantive simplification of national economies and strengthening of global economic ties. The goals determine the logic tendency of national economies for reducing the interest rate so as to gain the financial momentum and, consequently, fanning the crisis risk in the global financial system. The global financial system became the substance of global economic processes, which determined development opportunities of national economies. I reveal what countries have the high and low financial momentum. Conclusions and Relevance. Being the unity of antipodes in the modern economic development, financial momentum causes countries to lose their economic identity, making them just functions of the global financial system. The cyclical development model of national economies is replaced with the metron model that rests on fluctuating advanced economies with the low financial momentum at its bottom and emerging economies at its top. The findings crystallize the concept and new competencies for a person who decide on the determination and performance of financial regulation activities.


Author(s):  
Ana Rita Damas Oliveira ◽  
Paulo Alexandre Guedes Lopes Henriques ◽  
Teresa Cristina Clímaco Monteiro de Oliveira

Much has been written about the link between HR and performance, however consensus has yet not been found concerning the understanding on how that relationship comes together. Empirically, no direct impact has been found and research has only suggested an indirect impact. Consequently, the Strategic HRM field is particularly interested on the understanding of the mediating variables that impact the organization performance. Besides the integrated and business strategy alignment of the HR function, it should be considered that it is the people (HR) of the organization and not their practices that determine the company´s competitive advantage. (Messersmith & Guthrie, 2010) argue that it is the impact of those practices that represent “the true resource and enable a sustainable advantage over industry rivals”. The objetive of this research proposal is to study the impact of strategic human resources practices on the organization performance through a case study methodology, supported by longitudinal data. Namely, the project aims to achieve a deeper understanding of the variables that affect the process stream during strategy implementation. How the HR practices impact on people? And why human resources are the most valuable asset? These core premises are in line with the most recent economic concerns about people productivity, employment policies and labor flexibility.


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