In a dynamic machining process, distortion in surface irregularity is a very complex phenomenon. Surface irregularities form a periodic representation of the tool profile with various kinds of disturbance in a broad range of changes in the height and length of the profile. To discern these irregularity disturbances, interactions of the tool in the form of changes perpendicular and parallel relative to the workpiece were analyzed and simulated. The individual kinds of displacement of the tool relative to the workpiece introduce distortions in the changes of height and length. These changes are weakly represented in standard height and length irregularity parameters and their discernment has been found through amplitude-frequency functions.

This paper deals with the experimental validation of the suitability of the method for measuring radial variations of components on the process tool. The tests were conducted using a computerized PSA6, which was compared to a Talyrond 73. The results of measurement of roundness deviations as well as roundness profiles were analyzed for a sample of 70 shafts. The roundness deviations were assessed by determining the experimental errors, while the profiles obtained with the tested device were compared to those registered by the reference device using three correlation coefficients.

The article describes a test stand with a spindle equipped with an active bearing preload system using piezoelectric actuators. The proper functioning of the spindle and the active system was associated with the correct alignment of the spindle shaft and the drive motor. The article presents two methods of shaft alignment. The use of commonly known shaft alignment methods with dial indicators is insufficient from the viewpoint of being able to control this preload. This work aims at making the readers aware that, for systems with active bearing preload, the latest measuring devices should be used to align the shaft. The use of commonly known methods of equalization with dial gauges is insufficient from the point of view of controlling this preload. Increasing the accuracy of shaft alignment from 0.1 to 0.01 mm made it possible to obtain a 50% reduction in the displacement of the outer bearing ring during spindle operation.

The purpose of the paper is to present the author’s reflections on the origin and popularity

of various approaches to maintenance and improvement of production processes, their

terminological consistency, understanding, and practical application of their principles. The

author’s reflections are based on his observations made over his many years of activity as

a lecturer and consultant in the area of production engineering and management. It was

shown that there is a need to make scientists and practitioners aware of the relatively large

degree of freedom in defining the scope and way of application of strategies of continuous

improvement. The author’s proposal is to refer to all approaches to maintenance and improvement

of production processes with the title “Strategies of Efficient Action” and all

supporting methods as “Practices of Efficient Action”.

Considerations presented in the paper can be useful in more and more efficiently applying

the power of TQM, Six Sigma, Lean Manufacturing and other strategies of processes

maintenance and improvement in the daily activities of companies.

In recent times, the concept of hard turning has gained awareness in metal cutting as it can apparently replace the traditional process cycle of turning, heat treating, and finish grinding for assembly of hard, wear-resistant steel parts. The major apprehension in hard turning is the tool vibration, which affects the surface finish of the work piece, has to be controlled and monitored. In order to control tool vibration in metal cutting, a magnetorheological fluid damper which has received great attention in suppressing tool vibration was developed and used. Also an attempt has been made in this study to monitor tool vibration using the skewness and kurtosis parameters of acoustic emission (AE) signal for the tool holder with and without magnetorheological damper. Cutting experiments were conducted to arrive at a set of operating parameters that can offer better damping characteristics to minimize tool vibration during turning of AISI4340 steel of 46 HRC using hard metal insert with sculptured rake face. From the results, it was observed that the presence of magnetorheological damper during hard turning reduces tool vibration and there exist a strong relationship between tool vibration and acoustic emission (AERMS) signals to monitor tool condition. This work provides momentous understanding on the usage of magnetorheological damper and AE sensor to control and monitor the tool condition during turning of hardened AISI4340 steel.

The main objective of the present work was to determine the effect of powder composition on microstructure and properties of iron-base materials used as matrices in diamond impregnated tools. The Fe-Cu-Ni powders premixed and ball-milled for 30 hours, were used for the experiments. The influence of manufacturing process parameters on microstructure and mechanical properties of produced sinters was investigated. Sintering was done by hot-pressing technique in graphite mould. The powders were consolidated to a virtually pore-free condition during 3 minutes hold at 35MPa and 900°C. Investigations of the sintered materials included: density, hardness, static tensile test and X-ray diffraction (XRD) analysis. Microstructural and fractographic observations were also made with a scanning electron microscope (SEM). The obtained results indicate that the sintered parts have a high density, close to the theoretical value, good plasticity, relatively high hardness and yield strength, and are characterized by a coarse-grained microstructure.

The paper presents results of studies on linear synchronous motors controlled in CNC feed axes through an intelligent digital servodrive. The research includes a conceptual design of an open servodrive control system and identification of dynamic models of a test stand with an open CNC system. Advantages of robust control over the classic one are discussed. A hybrid predictive approach to robust control of milling machine X-Y table velocity is proposed and results of simulation tests are presented. Was prepared during the work for the Ministry of Science and Higher Education grant number N N502 336936, (acronym for this project is M.A.R.I.N.E. multivariable hybryd ModulAR motIon coNtrollEr), while its main purpose is the development of new rob ust position/velocity model-based control system, as well as to introduce the measurement of the actual state into the switching algorithm between the locally synthesized controllers. Such switching increases the overall robustness of the machine tool feed-drive module. The paper is the extended version of material proposed in [10].

A short literature survey which justifies coating of ceramic cutting inserts is presented. The results reported are on selected nitride

coatings, in particular nanoscale multilayer, with layers of type Ti-Zr-N, TiN, ZrN and (TiAl)N, deposited by the arc PVD method on oxidecarbide ceramic cutting inserts of type TACN and TW2 produced at the Institute of Advanced Manufacturing Technology. Measurements and quality assessments were made, including of thickness of the coatings and of their constituent micro and nanolayers, microhardness of the coating and of the substrate, surface roughness of the inserts and of the cylindrical workpieces turned with these tools. Lifetimes of the coated and uncoated inserts were compared in turning an alloy tool steel. A significant increase in lifetime of the coated TW2 cutting tools was shown.

Aluminum 6082-T6 panels were joined by friction stir welding utilizing a bobbin tool. A thermal simulation of the process was developed based upon machine torque and the temperature dependent yield stress utilizing a slip factor and an assumed coefficient of friction. The torque-based approach was compared to another simulation established on the shear layer methodology (SLM), which does not require the slip factor or coefficient of friction as model inputs. The SLM simulation, however, only models heat generation from the leading edges of the tool. Ultimately, the two approaches yielded matching temperature predictions as both methodologies predicted the same overall total heat generation from the tool. A modified shear layer approach is proposed that adopts the flexibility and convenience of the shear layer method, yet models heat generation from all tool/workpiece interfaces.

The touch trigger probe plays an important role in modern metrology because of its robust and compact design with crash protection, long life and excellent repeatability. Aside from coordinate measuring machines (CMM), touch trigger probes are used for workpiece location on a machine tool and for the accuracy assessment of the machine tools. As a result, the accuracy of the measurement is a matter of interest to the users. The touch trigger probe itself as well as the measuring surface, the machine tool, measuring environment etc. contribute to measurement inaccuracies. The paper presents the effect of surface irregularities, surface wetness due to cutting fluid and probing direction on probing accuracy on a machine tool.

The specificity of tool provisioning is conditioned using tooling, the quantity of which

exceeds the nomenclature of the manufactured goods considerably. Therefore, for modern

enterprises, first-priority issues are harmonizing the processes of tool provisioning systems,

increasing the level of the reaction of this system to changes, obtaining operational control

over the production system, and, thus, improving the efficiency of the production process.

In this paper, a mathematical model of decision-making based on determining the optimal

strategy for the process flow was proposed to improve the efficiency of the information

system for quality management of tool provisioning. It is suggested to use the sustainable

development factor of information system for quality management of tool provisioning to

make decisions about the path of the tooling process, which considers the requirements of

international standards for management systems (ISO 9001, ISO 45001, etc.). This model

is based on the application of graph optimization theory, fuzzy logic, and Markov chains.

The use of this model is universal and will increase the validity of operational management

decisions, increase productivity, reduce resource dependency, and, therefore, reduce the

costs of tool provisioning, which directly affects the cost of production and competitiveness

of the enterprise as a whole.

The paper concerns a risk assessment and management methodology in critical infrastructures. The aim of the paper is to present researches on risk management within the experimentation tool based on the OSCAD software. The researches are focused on interdependent infrastructures where the specific phenomena, like escalating and cascading effects, may occur. The objective of the researches is to acquire knowledge about risk issues within interdependent infrastructures, to assess the usefulness of the OSCAD-based risk manager in this application domain, and to identify directions for further R&D works. The paper contains a short introduction to risk management in critical infrastructures, presents the state of the art, and the context, plan and scenarios of the performed validation experiments. Next, step by step, the validation is performed. It encompasses two collaborating infrastructures (railway, energy). It is shown how a hazardous event impacts the given infrastructure (primary and secondary eects) and the neighbouring infrastructure. In the conclusions the experiments are summarized, the OSCAD software assessed and directions of the future works identified.