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Imperialism and Finance
Published in Leo Alting, Geoffrey Boothroyd, Manufacturing Engineering Processes, 2020
The grinding tools are available in many geometrical shapes, such as wheels, segments, bands, and so on. The most frequently used grinding tool is the grinding wheel used for cylindrical or plain grinding. Grinding offers close dimensional control and fine surface finishes and has become extremely important in recent years, because of the increasing demands of high accuracy and surface quality. Formerly, grinding was used only for finishing operations, but a rapid development is taking place with regard to roughing (high-speed) grinding, which may substitute for turning, for example.
Silicon Carbide Surface Quality Prediction Based on Artificial Intelligence Methods on Multi-sensor Fusion Detection Test Platform
Published in Machining Science and Technology, 2019
Yawei Zhang, Beizhi Li, Jianguo Yang, Xiao Liu, Jinqiang Zhou
A subtle change from process parameters and from grinding conditions can cause a significant error due to the hard and brittle material such as silicon carbide in high speed grinding process. Hence, a test platform with functions of monitor and measurement should be developed for detection and measurement of changes of force, vibration, temperature and noise. These signals from test platform can be processed and then can form data to be analyzed. The multi-sensor fusion detection test platform includes three modules as shown in Figure 1: high speed grinding process module, high precision multi-sensor detection module and data acquisition and analysis module, which meet the demand of covering a wide range of process conditions. It is the key factor to develop the multi-sensor fusion detection test platform because the high precision test unit with anti-interference is the basis to achieve the accuracy of test results.
High-recycled-content hydraulic cements of alternative chemistry for concrete production
Published in International Journal of Sustainable Engineering, 2018
Faris Matalkah, Mohamed Mahmoud, A. G. N. D. Darsanasiri, Nastaran Abdol, Parviz Soroushian, Anagi M. Balachandra
Figure 3 compares the cube concrete specimens prepared with the brick-based hydraulic cement subjected to mechanochemical processing via ball-milling and high-speed grinding. The hydrated concrete is observed to have the red colour of brick. This points at a common feature of alkali aluminosilicate cements where a lower degree of hydration than Portland cement is adequate for providing binding effects. With ball-milling (Figure 3(a)), a uniform surface efflorescence was noted. This was not the case with high-speed grinding (Figure 3(b)). Surface efflorescence with alkali aluminosilicate cements has been attributed to the migration of sodium cations to the surface where they carbonate and form sodium carbonate. This phenomenon points at the relative mobility (and abundance) of sodium cations within hydration products, which has been encountered in alkali activated binders irrespective of their production method (Škvára et al. 2009). This phenomenon relates to the specific chemistry of the hydration products, and tends to be more pronounced with room-temperature curing.
Synthesis, characterizations and application of polyaniline-paint as anticorrosion agent
Published in Inorganic and Nano-Metal Chemistry, 2021
Fatima Assassi, Nassira Benharrats
To obtain 100 g of paint, all the raw materials necessary for the formulation are weighed, then the anticorrosion agent (phosphate zinc or conductive polymer) is introduced gradually and with moderate stirring. Then, the epoxy resin, the pigments, the fillers, the additives and the solvent mixture are added progressively underlow stirring. After that, 50% by weight of glass beads are added to the mixture. These are used as a grinding element under high-speed grinding in aim to obtain paint with fineness grain size. The fineness of grinding is determined by standardized control called gauge fineness. When a good fineness is obtained, the paints are filtered to remove the glass beads, and then a hardener (amine type with a ratio of paint/hardener 86/14) is added.