Research on selection of abrasive grain size and cutting parameters when grinding of interrupted surface using aluminum oxide grinding wheel with ceramic binder

In this article, a study on intermittent surface grinding using aluminum oxide grinding wheel with ceramic binder is presented. The testing material is 20XH3A steel (GOST standard – Russian Federation). The testing sample has been sawn 6 grooves, with the width of each groove of 10 mm, the grooves are evenly distributed on the circumference of sample. The testing sample resembles a splined shaft. An experimental matrix of nine experiments has been built by Taguchi method, in which abrasive grain size, workpiece speed, feed rate and depth of cut were selected as input variables. At each experiment, surface roughness (Ra) and roundness error (RE) have been measured. Experimental results show that the aluminum oxide and ceramic binder grinding wheels are perfectly suitable for grinding intermittent surface of 20XH3A steel. Data Envelopment Analysis based Ranking (DEAR) method has been used to solve the multi-objective optimization problem. The results also showed that in order to simultaneously ensure minimum surface roughness and RE, abrasive grain size is 80 mesh, workpiece speed is 910 rpm, feed rate is 0.05 mm/rev and depth of cut is 0.01 mm. If evaluating the grinding process through two criteria including surface roughness and RE, depth of cut is the parameter having the greatest effect on the grinding process, followed by the influence of feed rate, workpiece speed, and abrasive grain is the parameter having the least effect on the grinding process. In addition, the effect of each input parameter on each output parameter has also been analyzed, and orientations for further works have also been recommended in this article

Effect of the Abrasive Grain Distribution on Ground Surface Roughness

In order to reduce the grinding surface roughness, it is necessary to optimize the grinding conditions; this requires clear understanding of the relationship between the grinding conditions and ground surface roughness. Therefore, various studies have been carried out over the decades on the ground surface roughness and have proposed statistical grinding theory to define the relationship between the grinding conditions and ground surface roughness. However, the statistical grinding theory does not consider a few grinding conditions such as abrasive grain shape and distribution of abrasive grain, which affect the ground surface roughness. In this study, we construct a statistical grinding theory that considers the effect of abrasive grain distribution and improves the accuracy of the theoretical analysis of the ground surface roughness.

Development of Abrasive Grain Coating Technology Protective Polymer Casing for Water-Abrasive Cutting

The article presents the technology of covering abrasive grains with a protective polymer shell, which allows to reduce the wear of the focusing tube of the nozzle of a hydroabrasive installation. A description of the manufacturing process of a prototype abrasive with a polymer coating in a fluidized bed is presented in order to determine the critical processing modes at which a high-quality product will be obtained in a minimum operating time of the installation.

Process optimization and removal of phenol formaldehyde resin coating using mechanical erosion process

Consumption of coated abrasive discs in various automobile and pipe fitting application is increasing, due to its good surface finish. Coated abrasive disc consists of single layer of abrasive grain bonded to a fibre backing. The major portion of the disc is comprised of fibre backing. But the sustainability of the fibre backing is low and is dumped as waste after usage. The present work deals with the removal of resin coating and recovery of fibre backing from the spent coated abrasive discs using physical separation process such as sand blasting technique. Initially, the recovery experiment was carried out based on L16 orthogonal array. The factors and levels chosen for the experiments were erodent pressure (0.2, 0.4, 0.6 and 0.8 MPa), erodent size (36, 60, 80 and 120 grit), disc orientation (30, 45, 60 and 75°) and number of times flexing (5, 10, 15 and 20). The experimental result shows that erodent size and erodent pressure have a major impact on recovery of the fibre backing. The surface structure of the recovered backing was analysed using scanning electron microscopy and optical microscopy. The recovered backing was very much useful for the coated abrasive industry as the flexible backing and support material for abrasive grain coating.

Study of the mineralogical and grain size composition of the regenerated grain from bearing sludge

The composition of sludges (wastes of bearing industry enterprises) is determined by the characteristics of the abrasive tool used upon manufacturing, grade of the processed material, cutting-tool lubricant (CTL) and modes of treatment. We present the results of studying the mineralogical and grain size composition of the regenerated grain from bearing sludges. The material under study is shown to have the following composition, %: abrasive particles — 5 – 8, metal particles — 50 – 90, binder — 2 – 5, balance — SOG, oil and various pollutants. The dispersion of solid particles ranges within 0.1 – 0.3 mm. The abrasive grains have a predominantly splintery shape, the individual binder particles being observed on their surface. The interlayer-cemented aggregates of two — three crystals and a large number of small splintery particles are also present. It is shown that the samples with a regenerated material containing fine abrasive grain and metal particles as a filler exhibit the highest mechanical strength and thermal conductivity. The results obtained can be used when using regenerated abrasive grain from sludge for manufacturing, e.g., grinding wheels, preparation of a molding abrasive mixture, etc.

Investigation Of Methods To Reduce The Micro Hardness Of Marble Aggregates

This research paper describes the surface degradation properties of brittle and plastic-brittle materials like marble, crumbling body properties, load acceleration parameters and effects associated with the environment in which grinding is performed. When applied to marble filler in mosaic coatings, first of all, abrasive erosion occurs and a large number of cemented abrasive grain surfaces are removed by means of grinding binders, i.e. a micro-scratch process.

A Method for Tribological Measurements of Coated Abrasives using a Rheometer

Coated abrasives (sandpaper) are imperative in various industrial areas, including the automotive and the metal industry. An exact outcome is often highly appreciated in abrasion processes, which means that the wear process must be precisely controlled. In this paper, a new method for analyzing the grinding process of coated abrasives is proposed. In order to study the grinding properties of sandpaper, a tribology cell was connected to a rheometer. The experiments consisted of unlubricated (dry) steel balls-on-disc experiments on coated abrasive with aluminum oxide grains. The friction and wear data showed that the rheometer equipped with a tribology cell can be used to measure different tribological parameters, such as the friction coefficient and the Gap. The wear process was investigated over a range of abrasive grain sizes (9–40 µm) and a variety of different loads (1–10 N). Results from these experiments showed that the abrasive wear increased with increasing particle size and normal load. Hence, it is proposed that this method is a reliable approach for investigating the wear process of coated abrasives.