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IN modern machining practice, precision grinding (the operation known in France as “rectification” is carried out on a limited number of parts and the use of the term immediately suggests the type of component usually subjected to this method of working—the gear wheel.

The purpose of this paper is to evaluate surface integrity of quenched steel 1045 ground drily by the brazed cubic boron nitride (CBN) grinding wheel and the black SiC wheel, respectively. Surface integrity, including surface roughness, sub-surface hardness, residual stresses and surface morphology, was investigated in detail, and the surface quality of samples ground by two grinding wheels was compared.

In the present work, surface integrity of quenched steel 1045 machined by the CBN grinding wheel and the SiC wheel was investigated systematically. All the specimens were machined with a single pass in the down-cutting mode of dry condition. Surface morphology of the ground specimen was observed by using OLYMPUS BX51M optical microscopy. Surface roughness of seven points was measured by using a surface roughness tester at a cut-off length of 1.8 mm and the measurement traces were perpendicular to the grinding direction. Sub-surface micro-hardness was measured by using HVS-1000 digital micro-hardness tester after the cross-section surface was polished. The residual stress was tested by using X-350A X-ray stress analyzer.

When the cut depth is increased from 0.01 to 0.07 mm, the steel surface machined by the CBN wheel remains clear grinding mark, lower roughness, higher micro-hardness and higher magnitude of compressive stress and fine microstructure, while the surface machined by the SiC grinding wheel becomes worse with increasing of cut depth. The value of micro-hardness decreases, and the surface roughness increases, and the surface compressive stress turns into tensile stress. Some micro-cracks and voids occur when the sample is processed by the SiC grinding wheel with cut depth 0.07 mm.

In this paper, the specimens of quenched steel 1045 were machined by the CBN grinding wheel and the SiC wheel with various cutting depths. The processing quality resulted from the CBN grinding wheel is better than that resulted from the SiC grinding wheel.

The purpose of this study is to investigate the characteristic and function of oxide film formed on grinding wheel in electrolytic in-process dressing (ELID) precision grinding and improve the quality of ELID grinding.

Dynamic film forming experiments were carried out with a simulation device close to the actual processing conditions. Then, the ELID grinding experiments of bearing rings were performed using grinding wheels with good film forming effect. The experiment was designed by quadratic regression general rotation combination method. The influence of grinding depth, electrolytic voltage, duty cycle and grinding wheel linear speed on grinding effect is analyzed.

A mathematical model for the formation rate of oxide film was established. The experiments show that the composition of grinding wheel and grinding fluid, as well as the electrical parameters, influence the film forming effect. Thus, the oxide film plays an important role in ELID grinding.

This study provides a reference for the design and selection of grinding wheel and grinding fluid and the setting of process parameters in ELID grinding.

This study aims to apply an electrochemical grinding (ECG) technology to improve the material removal rate (MRR) under the premise of certain surface roughness in machining U71Mn alloy.

The effects of machining parameters (electrolyte type, grinding wheel granularity, applied voltage, grinding wheel speed and machining time) on the MRR and surface roughness are investigated with experiments.

The experiment results show that an electroplated diamond grinding wheel of 46# and 15 Wt.% NaNO₃ + 10 Wt.% NaCl electrolyte is more suitable to be applied in U71Mn ECG. And the MRR and surface roughness are affected by machining parameters such as applied voltage, grinding wheel speed and machining time. In addition, the maximum MRR of 0.194 g/min is obtained with the 15 Wt.% NaCl electrolyte, 17 V applied voltage, 1,500 rpm grinding wheel speed and 60 s machining time. The minimum surface roughness of Ra 0.312 µm is obtained by the 15 Wt.% NaNO₃ + 10 Wt.% NaCl electrolyte, 13 V applied voltage, 2,000 rpm grinding wheel speed and 60 s machining time.

Under the electrolyte scouring effect, the products and the heat generated in the machining can be better discharged. ECG has the potential to improve MRR and reduce surface roughness in machining U71Mn.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2023-0341/

The granular structure of a grinding wheel determines its performance remarkably when grinding. Nowadays, grinding wheels are man-made porous conglomerates of hard abrasive grains bonded with a binder. As an engineered material, it would be interesting to foresee the behaviour of the wheel, but it is hindered under its complex heterogeneous nature. Recently, some models based on the discrete element method (DEM) have been presented to model the grinding wheel. This paper aims to identify and propose a framework that must comply with such models and to identify new applications for DEM models in grinding.

First, the characteristics of the grinding wheel are described. In this way, the framework of DEM models of a grinding wheel material is developed, reproducing both the granular morphology and stiffness.

The paper asserts a promising future that provides the DEM in the modelling of grinding.

The potential of DEM in grinding is analysed, proposing new applications. It can be used as topography model, which can also model the stiffness. In addition, DEM opens a new interesting research line: the modelling of the grit breakout. It draws up the development of essential dressing and wear models.

The purpose of this paper is to simplify the testing of coolants for grinding in the automotive industry.

A simple equipment is developed to test the coolant, by simulating the coolant‐grinding wheel‐workpiece interface and measuring in terms of grinding parameters.

It was found that the simulator could indicate the performance trends that closely match the actual grinding conditions.

Since this is a general system, it has to be customised with individual settings of the machining parameters for a meaningful interpretation and for comparison between machines.

This equipment will simplify the selection of coolants for grinding and serve as a pre‐qualifier before approving for trials in full‐scale shopfloor conditions.

The design of the equipment is new and provides an alternate for the otherwise costly, full‐scale evaluation of coolants on the shopfloor.

The purpose of this paper is to summarize the status and characteristics of rail technology of high-speed railway in China, and point out the development direction of rail technology of high-speed railway.

This study reviews the evolution of high-speed rail standards in China, comparing their chemical composition, mechanical attributes and geometric specifications with EN standards. It delves into the status of rail production technology, shifts in key performance indicators and the quality characteristics of rails. The analysis further examines the interplay between wheels and rails, the implementation of grinding technology and the techniques for inspecting rail service conditions. It encapsulates the salient features of rail operation and maintenance within the high-speed railway ecosystem. The paper concludes with an insightful prognosis of high-speed railway technology development in China.

The rail standards of high-speed railway in China are scientific and advanced, highly operational and in line with international standards. The quality and performance of rail in China have reached the world’s advanced level. The 60N profile guarantees the operation quality of wheel–rail interaction effectively. The rail grinding technology system scientifically guarantees the long-term good service performance of the rail. The rail service state detection technology is scientific and efficient. The rail technology will take “more intelligent” and “higher speed” as the development direction to meet the future needs of high-speed railway in China.

The development direction of rail technology for high-speed railway in China is defined, which will promote the continuous innovation and breakthrough of rail technology.

THE Treaty of Rome is one of the least publicised, yet potentially most important, international documents of our time. Under that treaty the six signatory powers began on the first day of this year that process of tariff reductions which will, over the next twelve or fourteen years, reduce and ultimately abolish all tariffs and trade barriers between them. For all practical purposes six national economies will be welded into a single supranational authority, with a common trade and commercial policy. That is to re‐draw the economic map of Europe.

IN the current issue of the journal of the Institute of Practitioners in Work Study, Organisation, and Methods one of its Members, a Mr. E. Cule Davies, plausibly argues that ‘professional standards’ are interdependent with what he terms ‘practical results’. Mr. Davies cites a notional case of a company inviting a ‘specialist’ (the quote marks are his) to improve productivity in a given section and who gave their own professional work study practitioner the same objective to attain.

The third in a series giving suggestions for laboratory work on the various types of machine tool