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When the threads are obtained by using turning tools, various factors are able to affect the machining accuracy. In order to reveal the way in which these factors exert influence on the threading accuracy, an analysis of some proper situations of obtaining threads on universal lathes and using turning tools was developed. The analysis showed that the thread profile error could be essentially affected by the position of the cutting tool active edges relative to the workpiece. Taking into consideration the results of analysis, some aspects concerning the requirements to be met during the design of a device that could be used in experimental investigation of influence exerted by some factors on the threading accuracy are presented.

Maximization of productivity and minimization of cost with acceptable quality of the parts are the most important goals of the production. In machining multi-objective optimization is a real problem. For solving this problem modern optimization methods are used. In this paper is presented a multi-objective optimization of single-pass turning of stainless steel with coated carbide tool using performance diagrams.

Abrasive water jet is cutting tool capable to cut a wide range of materials. Investigation on perpendicularity deviation and surface roughness in abrasive water jet cutting of carbon steel is proposed in this paper. Full factorial design of experiment with three factors, abrasive flow rate, traverse rate and standoff distance, each in two levels is employed to investigate perpendicularity deviation and surface roughness. The analysis of means and analysis of variance are employed to determine effect of factors on perpendicularity deviation and surface roughness. Regression analysis was used to find correlation of perpendicularity deviation and surface roughness versus process factors. [ABSTRACT FROM AUTHOR]

The electrochemical machining process is based on the material removal from workpiece as a consequence of electrochemical reactions developed between the workpiece material and electrolyte, when both tool electrode and workpiece are found in an electrolyte and they are connected in the electric circuit of a direct current supply. Distinct factors could exert influence on the sizes of parameters of technological interest in case of electrochemical machining process. The paper presents the results of some theoretical considerations and experimental researches concerning the evolution of the work gap size and diminishing the test piece mass in case of using a conical active surface of the test piece and an aqueous solution of sodium chloride as electrolyte. The experimental results were mathematically processed and empirical mathematical models were determined. The empirical models and the graphical representations based on these empirical models illustrated the diminishing of the final gap size when the angle of conical surface increases and when the initial gap size is higher; the increase of voltage determines an increase of the final gap size. A similar influence is exerted when the test piece mass is considered as output factor. [ABSTRACT FROM AUTHOR]

The industrial practice needs sometimes small diameter external cylindrical surfaces obtained in workpieces made of difficult to cut materials. Such surfaces could be obtained by electrical discharge machining. An analysis of some machining schemes able to ensure obtaining external cylindrical surfaces was developed. An experimental investigation was designed and materialized on the base of a machining scheme which uses a plate electrode having small holes previously performed by drilling and a ram electrical discharge machine. The tool electrode achieved an up-down work motion. The experiments were developed in accordance with the principles valid in the case of a complete factorial experiment, on the test piece made of high speed steel. The experimental results highlighted the influence exerted by some experimental factors on material removal rate. The power type empirical mathematical function shows the influence exerted by pulse time, pulse off time and peak current intensity on the material removal rate. [ABSTRACT FROM AUTHOR]

The electrical discharge machining can be sometimes applied in order to obtain external cylindrical surfaces. Such a problem appeared as a consequence of the necessity to extract a cylindrical test sample from a part made of difficult to cut material. The analysis proved the possibility to use a tubular tool electrode and a classical machining scheme valid in the case of ram electrical discharge machining. The method of full factorial experiment was applied in order to design the experimental research. As input parameters, one considered the pulse on time, off time and discharge peak intensity. An investigation concerning the influence exerted by these input parameters on work speed was developed. A power type empirical mathematical model was determined by mathematical processing of the experimental results. The power type function and graphical representations proved the significant influence exerted by discharge peak current. [ABSTRACT FROM AUTHOR]

Optimization methods of machining processes are tools for improving product quality and reducing cost and production time. Modern optimization methods, among which genetic algorithms (GA) have been, used a lot during last two decades. This paper describes the optimization of machining processes by using genetic algorithms. Optimal parameters of machining (cutting speed and feed) were determined. Also, minimal cost for the turning process was achieved. [ABSTRACT FROM AUTHOR]

Laser cutting machines are used for precise contour cutting thin sheet. In industrial application nowadays various types and construction of laser cutting machines can be met. For contour cutting 3-D thin sheet parts laser cutting machines with rotation movements and laser robots are used. Laser generates the light beam, that presents a tool in working process. Application of laser cutting machines made possible good quality of products, flexibility of production and enlargement of economy. [ABSTRACT FROM AUTHOR]

Abrasive water jet cutting is an advance non-traditional machining technology. Process of abrasive water jet cutting uses a jet of high pressure and velocity water mixed with abrasive particles to cut the material by means of erosion. For efficient application of abrasive water jet cutting it is necessarily to define cutting data, especially traverse rate. In many cases manufacturers use separation cut, i.e. traverse rate at which the abrasive water jet can cut through material. In this case the productivity is maximal. Predictive models, in form of multiple power functions, for traverse rate of separation cut in abrasive water jet cutting of aluminium alloy are developed using regression analysis and genetic algorithms. [ABSTRACT FROM AUTHOR]

The laser cutting is a cost effective technology. This process is based on melting and evaporating material in very small, a well-defined area and a blownout of the cut by the assist gas. Laser cutting processes make heat action fully effective, affecting a work piece material due to the laser beam. Laser cutting is a high-temperature process, which characterizes the small heat affected zone. The paper gives a part of experimental investigations of laser cutting process, which analyses the cut quality by laser cutting. [ABSTRACT FROM AUTHOR]

Laser beam is a new universal cutting tool able to cut almost all known materials. Laser cutting is new attractive process for contour cutting thin sheet. Laser cutting process offer much advantages as like: narrow, straight-edged kerfs, minimum heat affected zones adjacent to the cut edge, no mechanical distortion of the work piece, absence of tool wear and hence replacement, the ability to cut materials regardless of their hardness. Laser cutting is applicable for final working of work pieces. Application of laser cutting made possible good quality of products, flexibility of production and enlargement of economy. [ABSTRACT FROM AUTHOR]