Investigation into Layered Manufacturing Technologies for Industrial Applications
Additive processes, which generate parts in a layered way, have more than 20 years of history can be defined as layered manufacturing. Layered manufacturing is gaining ground for rapid prototypes (RP), rapid tools (RT) and rapid manufacturing (RM) for production of functional parts. The paper describes which mechanism of layered manufacturing and definition and classification of rapid prototypes can be applied to complex geometries for long-term consistency. The paper demonstrates the application examples of layered manufacturing fulfilling the required physical, mechanical and geometrical properties. The most notable advantage is the integration of production planning and testing within the product development period.
Analysis of the different forms of application and types of cutting fluid used in plunge cylindrical grinding using conventional and superabrasive CBN grinding wheels
Abstract The work reported here involved an investigation into the grinding process, one of the last finishing processes carried out on a production line. Although several input parameters are involved in this process, attention today focuses strongly on the form and amount of cutting fluid employed, since these substances may be seriously pernicious to human health and to the environment, and involve high purchasing and maintenance costs when utilized and stored incorrectly. The type and amount of cutting fluid used directly affect some of the main output variables of the grinding process which are analyzed here, such as tangential cutting force, specific grinding energy, acoustic emission, diametrical wear, roughness, residual stress and scanning electron microscopy. To analyze the influence of these variables, an optimised fluid application methodology was developed (involving rounded 5, 4 and 3 mm diameter nozzles and high fluid application pressures) to reduce the amount of fluid used in the grinding process and improve its performance in comparison with the conventional fluid application method (of diffuser nozzles and lower fluid application pressure). To this end, two types of cutting fluid (a 5% synthetic emulsion and neat oil) and two abrasive tools (an aluminium oxide and a superabrasive CBN grinding wheel) were used. The results revealed that, in every situation, the optimised application of cutting fluid significantly improved the efficiency of the process, particularly the combined use of neat oil and CBN grinding wheel.
Coolant Induced Forces in CBN High Speed Grinding with Shoe Nozzles
Abstract In grinding operations, the motion of the grinding wheel continuously draws cooling lubricant into the grinding gap, building up a force between the grinding wheel and the workpiece. This coolant induced force may exceed the pure grinding normal force, especially in high-speed grinding. Dimension, shape and position errors are among the possible consequences. The aim of this paper is to describe a physical model simulating coolant induced forces during high-speed grinding with CBN and oil as lubricant. The authors also present a coolant feed system which can decisively reduce the coolant flow rate while eliminating the build-up of hydrostatic pressure.