Electro Discharge Machining (EDM) is one of the most popular methods of shaping objects, used mostly for surfaces with complex shapes and materials of great hardness which are difficult to machine. An increasing interest in machining processes and their influence on the natural environment and operators' health has led to research aimed to decrease their negative impacts by designing new machining modes or modifying the existing ones. The article analyzes those properties of EDM which pose a threat to the environment and health of EDM machine operators as well as presents directions of the development of EDM with respect to its environmental impact and application related characteristics.

Nowadays in grinding operations cooling and lubricating liquids are extensively used. Their application in many cases contributes to the lowering of the grinding temperature, energy consumption and improving surface quality. However, at the same time they pose a significant threat to the health of machine operators and contribute to the overall production costs. Therefore, there have been numerous attempts to eliminate or at least reduce their usage. In the presented investigation three methods of cooling and lubrication were used: with emulsion, minimum quantity lubrication (MQL) and grinding dry. The influence of these methods on the grinding force and surface roughness depended on the respective movements between the grinding wheel and workpiece and the selection of grinding speed. It was concluded that grinding dry of AISI 304 austenitic stainless steel leads to an increase of the grinding force whereas in MQL grinding the same force decreased. In the case of 304 steel the smallest values of surface roughness parameters appeared in MQL grinding compared to grinding dry and with emulsion.

Cooling and lubricating liquids widely used in the process of drilling perform many desirable functions. The most important ones are cooling and lubricating of the drilling bit and machined hole, which lowers the temperature and friction between the tool and drilled piece. Due to high costs related to the application of these liquids and their negative impact on the natural environment and work place more studies have been carried out aimed at reduction or elimination of cooling and lubrication liquids from machining processes. When the cooling liquid cannot be eliminated completely, the techniques of minimizing its amount are of great importance. The article presents research on the impact of the cooling and lubricating mode on the cutting force during drilling and surface roughness of the drilled surface in the hot-work tool steel X37CrMoV5-1 (AISI H11). The presented research was conducted with three modes of cooling and lubrication of the carbide drill bit: with emulsion, with MQL and dry, using a wide range of cutting speeds and feed rates. A considerable increase in the drilling force and the deterioration of the surface roughness was observed after drilling dry. Depending on the drilling conditions the values of the measured parameters were comparable or better with the MQL mode than those in drilling with emulsion.

W artykule zaprezentowano wyniki badań, wraz z ich analizą, wpływu warunków wiercenia w materiale kompozytowym włóknistym, stosowanym do budowy czołownic pojazdów szynowych, na wartość współczynnika delaminacji.SŁOWA KLUCZOWE: delaminacja kompozytów, materiały kompozytowe włókniste

Ciecze chłodząco-smarujące wywierają istotny wpływ na przebieg procesu skrawania i efekty technologiczne [1, 2, 7, 10]. Poza spełnieniem podstawowych funkcji obróbkowych oddziałują negatywnie na środowisko naturalne oraz stanowisko pracy, stanowią znaczny udział w kosztach wytwarzania kształtowanych przedmiotów [3, 10]. W celu wyeliminowania negatywnych skutków ich stosowania prowadzone są badania zmierzające do ich wyeliminowania lub istotnego ograniczenia. Coraz szersze zastosowanie znajduje frezowanie na sucho lub z minimalnym smarowaniem strefy skrawania (MQL) [4÷6, 8÷10]. Frezowanie na sucho i z udziałem cieczy chłodząco-smarującej było przedmiotem licznych badań [2, 3, 10]. Natomiast badania wpływu MQL na stan warstwy wierzchniej po frezowaniu w warunkach wysokich prędkości skrawania są nieliczne. Celem prezentowanych badań było określenie wpływu chłodzenia i smarowania strefy skrawania na chropowatość powierzchni po frezowaniu stali konstrukcyjnej C45 i stopu aluminium PA4 w warunkach wysokich prędkości skrawania.

The mode of application of cutting liquids in cutting processes determines the properties of the produced surface, workpiece dimensional accuracy, and tool wear, as well as the physical phenomena which occur during cutting. However, their application causes many ecological and social problems connected with environmental pollution and operator health. Their elimination or significant reduction demands a comparable machined surface quality in dry cutting conditions or with a minimized quantity of lubricant. The current paper presents results of research into the cutting process, describing the topographical surface properties obtained in dry and with minimum quantity lubrication (MQL) turning of AISI 316L steel, which have been compared with those obtained after a conventional supply of emulsion. Previous investigations performed on the impact of cutting environment on machined surface quality were usually made in dry or wet conditions. The surface texture was analysed on the basis of the surface roughness parameter Ra, neglecting other important surface features. For this reason surface hybrid roughness profile parameters and the Abbott-Firestone curve as well as the surface topography have been used in the present paper. The experimental results showed a considerable influence of the cutting zone environment and parameters on the cutting force, surface roughness, profile bearing ratio, and the occurrence of surface defects. The presented regression functions allow a calculation and prediction of surface roughness values as a function of cutting zone cooling and lubrication conditions and selected values of cutting parameters in the turning of AISI 316L steel.

Residual stresses in the surface layer exert a significant impact on functional aspects of machined parts. Their type and value depend on the workpiece and tool material properties, cutting parameters and cooling and lubrication conditions in the tool-chip-machined surface interface. As the effects of material properties and cutting parameters have been widely studied, the influence of cooling and lubrication conditions, especially minimum quantity lubrication (MQL) on the surface layer residual stresses and the relationships between them have not been investigated. In this paper the effects of dry, MQL cutting and cutting with emulsion conditions together with cutting parameters on residual stresses after turning AISI 316L steel were investigated. X-ray diffraction method was used for measuring superficial residual stresses in the cutting (hoop) and feed (axial) directions. Tensile residual stresses were detected in both directions and the values in the cutting direction turned out to be higher than in the feed direction. The effects of cooling and lubrication conditions largely depend on the selected cutting parameters, whose influence is linked to the cutting zone cooling and lubrication mode. Elaborated regression functions allow calculation and optimization of residual stresses in turning AISI 316L steel, depending on cooling and lubrication conditions as well as cutting parameters.

In machining operations cooling and lubrication liquids perform significant technological functions such as reducing temperature of the cutting area and determine machined surface layer characteristics. However their negative ecological effects force the industrial and scientific community to find an alternative means of cooling and lubrication of the cutting zone. The article shows the results of performed experiments of the influence of cooling and lubrication methods on the machined surface layer roughness and bearing ratio after turning C45 steel. The experimental results indicate that in correct chosen cutting parameters, the elimination of cutting liquids does not have to decrease the machined surface quality and makes it possible to reduce ecological burdens imposed by wet machining processes.

The cooling and lubricating liquids widely used in metal machining are more and more often considered to be harmful to the natural environment and human health. For economic and ecological reasons the industry and research institutions are searching for methods and measures to limit or eliminate them. This is naturally determined by the conditions that the quality of machined surfaces has to be the same or at least comparable to that obtained with conventional cooling methods. The article presents the results of research into the influence of cooling and lubrication on surface layer physical properties -microhardness and microstructure changes, after turning the C45 and X2CrNiMo 17-12-2 steel dry, with minimal quantity lubrication (MQL) and emulsion in a wide range of cutting parameters. Significant differences in the microhardness parameter HV0,02 and surface layer microstructure depending on the cutting zone cooling and lubrication conditions have been observed. The research has also shown that despite difficulty in turning X2CrNiMo 17-12-2 steel, properly selected cutting parameters help to limit or eliminate fluids used in conventional cooling and lubrication and still obtain comparable or even better surface layer

Machining with the use of cooling and lubrication liquids (called wet machining) is still the primary method of shaping constructional materials. However, economic and ecological factors cause that wet machining is being replaced by processes which use minimal quantities of cooling and lubrication liquids (MQL machining) or do not use them at all (dry machining). Eliminating cooling and lubrication from cutting processes results in higher temperatures during the cutting process and worse tribological conditions around the moving surfaces between the tool and workpiece. This, on the other hand, causes changes of the conditions in which the chip is formed and a different form of the chips. Another consequence is problems related to hot chips and difficulty measuring hot workpieces. The form of the chip is an important factor particularly noticeable in automated part manufacturing lines, where the chip has to be easily removable from the cutting zone especially if the parts are made of difficult-to-machine materials. This paper presents results of an investigation into the conditions of chip formation and its form in dry, MQL turning as well as in turning with emulsion. The machined materials include constructional steel C45 and austenitic stainless steel X2CrNiMo 17-12-2. The obtained results confirm a significant role of cooling and lubrication conditions which, however, depends on the selected cutting parameters and the properties of the workpiece material. The results also helped to select cutting conditions which are most suitable for automated machining.

At present coolants and lubricants are increasingly recognized as harmful factors for environment and machine operators' health. Industry and research institutions are looking for new means of reducing or eliminating the use of cutting fluids, both for economical and ecological reasons. This can be done if tool wear and tool life in dry and minimal quantity cooling and lubrication (MQL) conditions are comparable to those in wet machining. This paper presents an investigation into effects of the cutting zone cooling and lubrication on the tool wear in turning austenitic stainless steel AISI 316L using carbide inserts coated with (Ti,Al,Si)N layers. The tool wear results in dry turning and with minimum quantity lubrication are compared with conventional emulsion cooling. The rake face and flank wear parameters were investigated. The experimental outcomes indicate a significant influence of the cooling and lubrication conditions on the tool wear. Turning dry or with MQL increases tool wear. The application of MQL compared to turning with emulsion facilitates elimination or considerable reduction of machined material adhesion to the tool surfaces.

At present coolants and lubricants are increasingly recognized as harmful factors for environment and machine operators’ health. Industry and research institutions are looking for new means of reducing or eliminating the use of cutting fluids, both for economical and ecological reasons. This can be done if quality properties of machined surfaces and process parameters in dry and wet machining are comparable. This paper presents an investigation into the influence of cutting zone cooling and lubrication on surface roughness, waviness, profile bearing ratio and topography after turning C45 steel. Dry cutting and minimum quantity lubrication (MQL) results are compared with conventional emulsion cooling. Cutting forces and their components were put under examination as well. The experimental outcomes indicate that the cooling and lubrication conditions affect significantly the investigated process and surface properties. However, the impact of the cooling and lubricating technique depends to a large extent on the applied cutting parameters, namely the cutting speed and feed rate. Turning dry or with MQL with properly selected cutting parameters makes it possible to produce better surface topography characteristics than turning with conventional emulsion cooling. Apart from improving the surface properties the MQL mode of cooling and lubrication also provides environmental friendliness.

Residual stresses in a surface layer determine many exploitation characteristics of machined surface. Depending on their kind and the type of applied loading, the influence of residual stresses can be negative or positive. Tensile residual stresses usually exert highly detrimental impact on several functional aspects such as strength, fatigue life, corrosion, wear resistance, etc., whereas compressive residual stresses are considered to have a beneficial effect on these features. The residual stresses found in mechanical parts are mainly generated in the final steps of machining process and are highly dependent on the machining conditions used. The increasing trend in industrial practice to eliminate cutting fluids from machining processes substantially changes machining conditions and influences the relationship between factors causing residual stresses. The main purpose of the presented investigations was to identify the relationship between residual stresses in a surface layer and the method of cooling employed. Using the X-ray diffraction method, residual stresses generated in both the cutting (circumferential) and feed (axial) directions were analysed. On the basis of empirical results the influence of turning with and without the application of emulsion on residual stresses was identified for a broad range of cutting parameters. The results showed that the method of cooling and cutting parameters exert a substantial influence on residual stresses. In the used range of cutting conditions, tensile residual stresses were detected. The elimination of cutting fluid from a turning process of C45 steel increased the magnitude of residual stresses in the surface layer. Residual stresses in the cutting direction turned out to be higher than in the feed direction in most cases of cutting conditions.