International Journal of Abrasive Technology (5 papers in press)
Effect of small quantity lubrication on grindability of hardened AISI 4340 steel
by Sirsendu Mahata, Joydip Roy, Ankesh Samanta, Bijoy Mandal, Santanu Das
Abstract: The process of grinding is normally associated with generation of considerable amount of heat. To reduce thermal damages, grinding zone is often flooded with liquid coolant, most of which is wasted and may cause severe environmental pollution. In the present work, grindability of hardened AISI 4340 steel is assessed at various infeeds, using an eco-friendly vegetable oil applied by small quantity lubrication (SQL) technique, so as to reduce the quantity of coolant. At the same infeed, grinding is also performed by applying a uniform layer of semi-solid lubricant (grease) on the work surface. Comparison is made between the two methods in terms of force, surface roughness, specific grinding energy and observed chip forms. Results prove that SQL technique using vegetable oil is better than grease as a lubricant in terms of force requirement, while surface quality shows improvement with grease layer lapped on the work surface than with SQL technique.
Keywords: grinding; grindability; cooling; lubrication; SQL; roughness; force; eco-friendly manufacturing.
Development of cBN electroplated end-mill combined cutting and grinding for precision machining of CFRP
by Tatsuya Furuki, Yugo Kabaya, Toshiki Hirogaki, Eiichi Aoyama, Kiyofumi Inaba, Kazuna Fujiwara
Abstract: Carbon-fibre reinforced plastic (CFRP) has been applied to various fields because of its excellent mechanical properties. Generally, after fabrication with moulding, CFRP requires additional machining, such as cutting or grinding. As the cutting tool for CFRP, a diamond-coated end-mill with high wear resistance has been developed. However, burr or uncut fibre is easily formed. Meanwhile, in the case when a grinding wheel is used, the machining efficiency is low even though there are sharp edges with burr or uncut fibres. Therefore, there is a need for the development of a versatile tool that can achieve precision machining of CFRP with high efficiency. This study develops a cBN electroplated end-mill that is a combination of a cutting tool and a grinding wheel. This report shows that the developed tool is able to perform high-efficiency cutting like the diamond coated end-mill, and high-precision grinding like a diamond wheel.
Keywords: CFRP; cBN; electroplated end-milling; grinding; machining centre.
Study on the segmentation of abrasive grains in diamond tools
by Yanfen Lin, Congfu Fang
Abstract: Segmentation of abrasive images of diamond tools is the most important part of computer vision, which is the basis for detecting the state of diamond tools, such as the characteristics of diamond number, distribution, size and state. As diamond images have rich irregular background textures and reflective features, it is a major challenge to detect and segment these diamond images. The present work demonstrates an invalid edge elimination method for such images to segment and mat the diamond grains, which mainly consists of histogram, edge detection, and morphology. Based on the method, the part of diamond in the original images can be accurately and effectively segmented and matted. Then, the method is also used to segment and mat the diamond grains in other images of different diamond tools, and it also has a good segmenting and matting effect. Finally, the segmented and extracted diamond grains are used to analyse the diamond number, density and its wear state, the result indicates that the proposed method can be used in diamond tool detection.
Keywords: diamond tool; topography; abrasive grain; segmentation; matting.
Experimental Study on Abrasive Water Jet Machining (AWJM) of AA5083 in a range of thicknesses
by Gurusamy Selvakumar, Shanmuga Sundaram Ram Prakash, Nagarajan Lenin
Abstract: The objective of this study is to present the optimal machining parameters for abrasive water jet machining (AWJM) of Aluminium alloy 5083 (AA 5083) by employing Artificial Neural Networks (ANN) modelling for various material thicknesses. Al 5083 alloy finds vast applications in ship building, rail cars, vehicle bodies and exclusively for cryogenic applications. The experimental work was carried out by using Taguchi L18 orthogonal array to study the influence of the process parameters such as jet diameter, stand-off distance and abrasive flow rate for various ranges of thicknesses over the process yields namely material removal rate (mrr), surface roughness and taper error. Technological table for optimal machining of AA5083 alloy in AWJM was reported for ready to use in industry.
Keywords: abrasive water jet machining; aluminium alloy; Taguchi method; ANN; Pareto optimization; Technology table.
Chemical catalysts of Fenton reaction for single-crystal SiC based on nanoindentation
by Huazhuo Liang, jiabin Lu, Qiusheng Yan, Tao Song
Abstract: Aiming at production of single–crystal SiC for chemical mechanical polishing, Fenton reaction, and catalytic efficiency of FeSO4, Fe2(SO4)3, FeO, Fe3O4, and Fe2O3 were studied. The mechanical properties are obtained by nanoindentation experiments. Different catalysts can promote Fenton reaction, and all reaction layers formed with the same chemical composition,atomic structure, and hardnessat 1.5 GPa. When Fe3O4 was used as catalyst in Fenton reaction, the effect was optimal because its hardness and modulus remained low. After 2 min, the thickness of reaction layer had reached 200 nm, which can fully meet requirements of CMP polishing. Fenton reaction depends on ability of catalyst to ionise Fe2+. The higher concentration of Fe2+, the higher concentration of •OH, and the faster reaction rate of SiC surface material.
Keywords: Single-crystal SiC; Fenton reaction; catalyst; nanoindentation.