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Recent Trends of Cutting Fluids and Lubrication Techniques in Machining
Published in Yashvir Singh, Nishant K. Singh, Mangey Ram, Advanced Manufacturing Processes, 2023
Metalworking fluids are used in order to enhance the surface integrity of parts, increased tool life, etc. However, cutting fluids cost nearly 17 percent of the manufacturing cost. Besides this, almost all the conventional cutting fluids are prepared by mixing with water, increasing water consumption. Apart from the economic perspective, cutting fluids negatively impacts the environment through contamination of soil, polluting air and water. Besides this, cutting fluids creates serious health issues for the metalworking industry, like ingestion, toxicity, inhalation, and skin irritation. The National Institute of Occupational Safety and Health (NIOSH) [9–10] report shows oil-based cutting fluids causing ingestion, irritation, and inhalation, which creates several health issues among the workers. The various ways through which cutting fluid could invade humans are mentioned in Figure 1.2.
Commercial Developments
Published in Leslie R. Rudnick, Synthetics, Mineral Oils, and Bio-Based Lubricants, 2020
Metalworking can be defined as changing the physical dimensions of a piece of metal, referred to as the workpiece. Metalworking operations can be split into two categories, cutting and forming. Cutting is the removal of metal from the workpiece in the form of chips. Cutting operations involve turning, milling, tapping, drilling, and grinding. In forming processes, the workpiece is subjected to enough pressure to cause the metal to flow into a predetermined configuration. Forming operations include hot and cold rolling, drawing, stamping, and coining. In both cutting and forming operations, friction from metal-to-metal contact causes wear and heat generation. Additional heat is generated as metal is stretched and deformed. Excessive heat build up will result in tool wear and poor surface finish. The purpose of metalworking fluids is to minimize friction by providing good lubricity and to remove heat from the tool and workpiece.
Windows
Published in Michael McEvoy, External Components, 2014
Cutting is done by mechanical saws or by grinding wheels, or by burning. Sheet metal is also cut by knife in a guillotine. Burning is precise enough to be used for cutting square mortices for a square member to pass through. Holes, including small mortices, are formed by drilling or punching. The latter may cause some deformation of the metal which, if there are many holes, may accumulate to measurable increases in length and width. Running joints are made with sleeves, bedded in mastic and tapped and screwed with countersunk screws, as shown in the diagram. Right-angled junctions between members (as for example between mullion and sill) are formed by scribing the end of the stopping member to the profile of the continuing member, filling it with a shaped cleat and screwing it to the continuing member, with a generous amount of mastic packed in the joint. A plain rectangular profile simplifies the junction. Complicated profiles call for a complicated cleat and may present difficulties in screwing up. Similarly, the scribing can only be done against flat planes but most importantly, the stopping element should be smaller than the continuing one it is adjoining so that it is quite clear of the slightly rounded angles of the continuing element. All this is illustrated in fig. 4.42 which shows typical column cover and mullion sections.
Development of a simplified design approach for shallow ballasted track forms with geocells reinforced sub-ballast
Published in International Journal of Rail Transportation, 2022
Since line opening, track geometry was monitored on a monthly basis using the Track Recording Coach. Figure 18 shows the standard deviation of track geometry calculated over a length of 200 m (a measure of track quality) within the treated section. From the figure, it can be noted that the initial track geometry standard deviation (SDi), right after installation when using geocells, has significantly improved by approximately 50% compared to the last recorded renewal in 2002. This indicates that the use of geocells improves the overall installation quality by achieving better construction tolerances, hence allowing for lower requirements for follow-up tamping regime. On the long term, it can be observed from the measurements that after the installation of the geocells, the rate of geometry deterioration has improved significantly by approximately 71% compared to the deterioration recorded after the last major renewal in 2002. This would lead to longer asset life and lower maintenance requirements. Table 5 provides a summary comparison between the track geometry performance after the last major renewal in 2002 and after the installation of geocells in 2016. In addition to the benefits in performance, the use of geocells has achieved the following: Reduced the cost of track renewal by approximately 22%.Reduced spoil and transport waggon requirements.Reduced the risk of compromising adjacent cutting slope stability and buried services due to shallower construction depth.
A comprehensive investigation of geometrical accuracy errors during WEDM of Al6061-7.5%SiC composite
Published in Materials and Manufacturing Processes, 2021
Kashif Ishfaq, Muhammad Umar Farooq, Saqib Anwar, Muhammad Asad Ali, Shafiq Ahmad, Ahmed M. El-Sherbeeny
The fabricated composites have been further processed to acquire essential shapes and dimensions for appropriate functions. Therefore, machining processes are employed to cut the material according to requirements. The cutting can be performed either employing traditional or non-conventional machining processes. Due to the improved hardness and other auxiliary characteristics of the material, machinability through conventional means is considered as uneconomical.[5]