Jin Oh Chung, Sang Ryul Go, Hee Bum Choi and Tae Kwan Son
This paper aims to investigate the temperature dependence of transfer film formation and friction coefficients in NAO friction materials with four different abrasive components…
Abstract
Purpose
This paper aims to investigate the temperature dependence of transfer film formation and friction coefficients in NAO friction materials with four different abrasive components, ZrO2, ZrSiO4, Al2O3 and Fe3O4.
Design/methodology/approach
8.5% SnS2 was added as a lubricating component to friction materials. Friction tests comprised 100 times of consecutive braking application for each friction material under constant temperature of 300°C, 400°C, 500°C and 600°C. After the friction tests, the friction surfaces of the counterpart disks were examined by scanning electron microscope to access the formation of transfer film.
Findings
Coefficients of friction depended on not only friction temperature but also friction history which is related to development of transfer film. The effect of the transfer film formation was to reduce the friction coefficients for most friction materials. Quantities of the transfer film formation varied with friction materials; at low temperature below 400° the transfer film formation was most active in the Fe3O4 materials, while at 600° it was the most active in the Al2O3 material. The effect of the lubricating component SnS2 was to suppress the formation of transfer film, thus enhancing friction coefficients.
Social implications
The enhancement of friction coefficients with addition of small amount of lubricating components such as SnS2 is expected to open a new approach in developing high performance-brake pads.
Originality/value
Temperature was the controlling parameter in the present test. Under these test modes, transfer film could be fully developed to access the role of the transfer film.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0427/
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Keywords
The concept of childhoods is both socially constructed and unique to particular social settings. Based on an ethnographic study of five Nepali children’s homes, I argue that the…
Abstract
The concept of childhoods is both socially constructed and unique to particular social settings. Based on an ethnographic study of five Nepali children’s homes, I argue that the localized contexts of these homes not only exist as spaces where youth negotiate their own unique statuses and futures but also where the social construction and fluidity of childhoods are most evident. By applying sociologist C. Wright Mills’ “sociological imagination,” we become best equipped to understand individual stories within these localized spaces as illustrative of what is ordinary and normalized at the local level, which in turn allows us to envision what is possible for broader society.
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Industrialization in capitalist societies ushered in the growth of trade unions and the development of union activities of industrial workers. In the late eighteenth and the early…
Abstract
Industrialization in capitalist societies ushered in the growth of trade unions and the development of union activities of industrial workers. In the late eighteenth and the early nineteenth centuries in the West when unionism began, trade unions took diverse forms. These forms varied by society and were significantly influenced by the country’s specific historical background and socioeconomic and cultural conditions. Yet such diverse union structures began to merge into “industrial unionism” in the late nineteenth century, which embraced all types of workers within the boundaries of an industry. Industrial unionism has been considered the organizational form that most effectively ensures the collective power of trade unions and their sociopolitical sway over contending forces, notably, the state and employers’ associations, and thus has remained a prototypical union system. Accordingly, nonwestern societies and latecomers to unionism in the West have modeled their unions on the basis of the industrial union structure.
Shubham Shankar Mohol and Varun Sharma
Additive manufacturing has rapidly developed in terms of technology and its application in various types of industries. With this rapid development, there has been significant…
Abstract
Purpose
Additive manufacturing has rapidly developed in terms of technology and its application in various types of industries. With this rapid development, there has been significant research in the area of materials. This has led to the invention of Smart Materials (SMs). The 4D printing is basically 3D printing of these SMs. This paper aims to focus on novel materials and their useful application in various industries using the technology of 4D printing.
Design/methodology/approach
Research studies in 4D printing have increased since the time when this idea was first introduced in the year 2013. The present research study will deeply focus on the introduction to 4D printing, types of SMs and its application based on the various types of stimulus. The application of each type of SM has been explained along with its functioning with respect to the stimulus.
Findings
SMs have multiple functional applications pertaining to appropriate industries. The 4D printed parts have a distinctive capability to change its shape and self-assembly to carry out a specific function according to the requirement. Afterward, the fabricated part can recover to its 3D printed “memorized” shape once it is triggered by the stimulus.
Originality/value
The present study highlights the various capabilities of SMs, which is used as a raw material in 4D printing.
Graphical abstract
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