Doğan Şimşek, Dursun Özyürek and Serdar Salman
The purpose of this study, the tribological behaviors at different temperatures of aluminium matrix composites (AMCs) with different amounts of ZrO2 added were investigated.
Abstract
Purpose
The purpose of this study, the tribological behaviors at different temperatures of aluminium matrix composites (AMCs) with different amounts of ZrO2 added were investigated.
Design/methodology/approach
Aluminium graphite (A356/2 wt% graphite (solid lubricant)) composite powders prepared by adding four different amounts (3 wt%, 6 wt%, 9 wt% and 12 wt%) of Zirconia (ZrO2) to the matrix were mechanically alloyed for 4 h. Wear tests were conducted at five different temperatures (20 °C, 100 °C, 180 °C, 260 °C and 340 °C) and for three different sliding distances (53 m, 72 m and 94 m) on the pin-on-disc type wear tester.
Findings
Results of the study showed that the highest hardness and density value were measured for 12% ZrO2 added AMC material. Wear test results showed that weight loss increases with increasing temperature; weight loss decreases at all temperatures with the increasing amount of reinforcement in the matrix.
Originality/value
In this paper, the tribological properties of aluminium matrix composites produced by the mechanical alloying method by adding different amounts of ZrO2 were determined by simulating the tribological properties at different loads and temperatures.
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Ramazan Köse, Levent Urtekin, Ali Ceylan, Serdar Salman and Fehim Findik
The aim of the research is to investigate the influence of ceramic coating on the wear performance of machine parts.
Abstract
Purpose
The aim of the research is to investigate the influence of ceramic coating on the wear performance of machine parts.
Design/methodology/approach
Ductile cast iron parts were coated using ceramics. Three ceramics were used for this purpose. These coated parts were subjected to wear tests under a stable load. A pin‐on‐disc wear test apparatus was used.
Findings
As a result of this study, the following findings are reported: According to ASTM G 99‐90 pin‐on‐disc experiments, Cr2O3 was found to be best coating material with low wearing rate. Within row, Al2O3 and ZrO2 can be given. According to the previous work, motor parts for example piston ring, cylinder liner and engine valve can be coated with ceramic. In this study, it is observed that the figure of merit is increased in this study. Only wearing data is given in this research. The other results are also supporter of the results taken from the wearing experiments. As a result, due to the decrease in heat loss and coaling stability of part can provide good results. With these, by coating there is a decrease in oil reduction.
Research limitations/implications
Coatings were limited with three ceramics, a stable load was used, and coated parts were subjected to wear test.
Practical implications
For future work, instead of using other coating materials, Cr2O3 is used for the best coating material with low wearing rate. By this process, working life of the machine parts can be extended and a number of economical advantages may also be obtained.
Originality/value
This paper fulfills identified information needs and offers practical help to the industrial firms working with ceramic coating and also to the academicians working on wear of materials.
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Serdar Salman, Ali Topal and Fehim Findik
The aim of the research is to increase piston and engine performance by using ceramic coated pistons instead of pistons which are manufactured from aluminum alloys and having a…
Abstract
Purpose
The aim of the research is to increase piston and engine performance by using ceramic coated pistons instead of pistons which are manufactured from aluminum alloys and having a coated flame chamber.
Design/methodology/approach
Thermal torch and thermal shock tests were performed on the pistons and some specimens of 1.5 mm thick were prepared according to ASTM standards; both have the same material characteristics. In the present work, plasma spray technique was used for ceramic coating.
Findings
It was found that the ceramic coating, which, when performed properly, has compatible expansion coefficient with the aluminum alloy pistons, increases performance of pistons and engines.
Research limitations/implications
Coatings were limited with one type of bonding and two ceramics, and coated parts were subjected to thermal torch and thermal shock tests.
Practical implications
For future work, instead of using other coating materials, stable yttria is used as the best coating material with optimum thermal resistance. By this process, working life of the machine parts can be extended and a number of economical advantages may also be obtained.
Originality/value
This paper fulfils the identified information and offers practical help to the industrial firms working with ceramic coatings and also to the academicians working on wear of materials.
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Mohammed Hamza Momade, Serdar Durdyev, Nguyen Van Tam, Shamsuddin Shahid, Jasper Mbachu and Yusra Momade
Vietnam's construction technology (CT) adoption is low when compared to other countries with similar gross domestic product (GDP) per capita resulting in lesser productivity. The…
Abstract
Purpose
Vietnam's construction technology (CT) adoption is low when compared to other countries with similar gross domestic product (GDP) per capita resulting in lesser productivity. The research objectives are: (1) To undertake an extensive literature review on CT adoption challenges; (2) To investigate CT adoption challenges unique to Vietnam's construction sector; and (3) To propose data-driven solutions for a greater rate of CT adoption.
Design/methodology/approach
A two-stage descriptive survey method was adopted in alignment with the research aim and objectives. Based on the literature review of 215 articles, a questionnaire was designed and administered to experienced construction managers (CM) to identify whether CT has been adopted, barriers to adoption, drivers, and the most popular CT tools. Descriptive statistics were used to summarize the characteristics of interest in the empirical dataset and SPSS-based inferential statistics to estimate the means, frequency counts, variance and test hypotheses that informed the drawing of conclusions concerning the research objectives.
Findings
The popular CT tools identified were Autodesk, Microsoft Office and Primavera. The most influential CT adoption barriers: (1) Unknow`n impact on productivity, (2) Late implementation of software in construction projects, (3) Lack of understanding of importance and needs in the construction industry (4) Lack of funds during budget planning for technological advances and implementation (5) Lack of experts required for technological change, and insufficient skills in the industry.
Practical implications
It is expected that the findings could inform data-driven regulatory and practice reforms targeted at increasing greater uptake of CT in Vietnam with potential for replication in countries facing similar adoption challenges.
Originality/value
The findings are intended to support data-driven regulatory and practice improvements aimed at improving CT adoption in Vietnam, with the possibility for replication in other countries facing comparable problems.
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Shahamak Rezaei, Jizhen Li, Shayegheh Ashourizadeh, Veland Ramadani and Shqipe Gërguri-Rashiti
Women Entrepreneurship has received increasing attention over the past decade. In particular, a new area dealing with women entrepreneurs in the developing societies. The aim of…
Abstract
Women Entrepreneurship has received increasing attention over the past decade. In particular, a new area dealing with women entrepreneurs in the developing societies. The aim of this study is how is women entrepreneurship in developing economies? More specifically, we are excavating various questions at the individual and institutional level. The results of this study contribute to understanding the importance of the context on women entrepreneurs’ activities. Additionally, it systematically provides a comprehensive framework at multilevel analyses to cover all aspects of women entrepreneurship in developing countries. Ultimately, knowing women entrepreneurship in developing countries helps policymakers provide a firm ground for self-employment of women.