Optimisation of grinding parameters for wheel loading and dressing
Grinding is a finishing process often used to produce desired surface roughness with required precision and quality. The performance of grinding wheel significantly depends on the nature of the wheel, morphology of the abrasive grits and the grinding parameters namely speed, feed and depth of cut. As the wheel is performing its grinding operation, its cutting surface is being loaded with metal particles of the workpiece. This wheel loading also affects the surface finish of the workpiece. Hence monitoring the grinding wheel loading and dressing at proper time intervals becomes mandatory to get the desired surface finish. In the quest of developing a low cost monitoring system, it is good enough to analyse the wheel loading on widely used metal specimens such as mild steel, HCHCr steel and aluminium under optimised cutting conditions using the conventional silicon carbide and aluminium oxide wheels for better evaluation of the results. In this work the grinding parameters are optimised by using ANOVA technique. A full factorial experiment was carried out at 5% level of significance, i.e. at 95% confidence level.
The Influence of High-Speed Milling Strategies on 3D Surface Roughness Parameters
Abstract Nowadays in die-cast manufacturing high speed milling are used to increase quality, accuracy and speed of material processing, also to reduce processing costs and save machining time. This paper is devoted for research of high-speed processing regimes impacts and their effect on the surface roughness quality of the machined material and 3D surface parameter values. This paper contains recommendations for die-cast manufacturers, deploying HSM, to improve machining process and obtain required surface quality. Analysis of variance methodology is used in this research. Research identify the most appropriate HSM regimes, that most important is chosen material type or material mechanical properties, influencing kurtosis of the scale-limited surface (Sku) and height of the bearing area ratio curve (Stp). Feed rate is most significant for texture aspect ratio (Str) and strategy type – influencing parameter of arithmetic mean surface height (Sa) and valley fluid retention index (Svi).
Investigation of surface treatment effects in micro-injection-moulding
Micro-injection-moulding as a replication method is one of the key technologies for micro-manufacture. An important stage in micro-injection-moulding which can affect the accuracy and mechanical properties of the produced components is part de-moulding. During this stage, part-mould forces can cause a variety of defects to micro-parts, including stress marks, deformation, fracture and stretching of the polymer structures. Therefore, in this paper, the effects of different surface treatments on the de-moulding behaviour of parts with micro-features are investigated. In particular, the de-moulding of a representative micro-part was studied as a function of two different tool coatings, diamond-like carbon and silicon carbide, in combination with four process parameters, employing the design of experiment approach. In addition, the results obtained using different combinations of process parameters were analysed to identify the best processing conditions in regards to de-moulding behaviour of polycarbonate and acrylonitrile butadiene styrene micro-parts when utilising these two coatings.