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The heat generated during the cutting processes significantly influences the manufacturing accuracy. For many machining tasks, the use of cooling lubricant is essential to achieve the necessary cooling and lubricating effect in the cutting zone. A reduction of a coolant supply due to resource-efficient or ecological efforts has an impact on the temperature field in the cutting tool and clamping system, which affects the thermal behavior of the frame structure and can cause its thermo-elastic deformations leading to machining inaccuracies. In this paper, the multi-phase CFD model for simulation of liquid coolant flow around the cutting tool was developed. The effect of rotation of the cutting tool causing turbulences was taken into account and the simulation of coolant flow was based in Eulerian approach as a continuous flow. Furthermore, this paper considers the modification of the simulation model for thermal simulations of the influence of coolant flow on the temperature field of the cutting tool and clamping system. [ABSTRACT FROM AUTHOR]

The paper presents a numerical simulation of thermal induced tool displacement during milling operation. An unidirectional finite element model is developed which consists of two sections. A CFX model and a thermal transient model. With the aid of CFX module, the conjugated heat transfer between milling tool and coolant fluid is described. The result of these efforts is the body temperature field of the end mill cutter due to thermal load, which is the thermal fingerprint of the cutting process. Subsequently the calculated body temperature field is linked with a transient-structural module to calculate the resulting thermal elastic displacement of the milling cutter. The thermo-elastic displacement of the tool is determined by examining a pilot node at the tip of the end mill, whose displacement is calculated in relation to the global coordinate system of the model. [ABSTRACT FROM AUTHOR]

The rising requirements in cutting operations for higher performance and higher efficiency respecting also environmental phenomena are influencing the use of different coolants and flushing conditions. In machining difficult-to-cut materials, in particular high-temperature materials, conventional emulsion cooling is unsuitable due to the insufficient cooling effect and the energy and cost intensive equipment required. For this reason new cooling and lubricating strategies have to be developed and investigated. Using hybrid processes, mainly by superposition of various cooling strategies, offers the potential to extend the existing technological process limits of conventional cutting processes. The paper introduces theoretical, experimental and simulation results with various innovative cooling strategies, such as high-pressure cooling, cryogenic cooling and aerosol dry lubrication in grooving, turning and drilling and derives the appropriate field of application for each flushing strategy. [ABSTRACT FROM AUTHOR]

An increased incidence of E. coli sepsis has been observed in neonates given intramuscular iron-dextran for prevention of iron deficiency. Mechanisms for this apparent effect on susceptibility to infection were investigated by comparing phagocytic and antibacterial functions in paired samples of venous blood from 7 infants, median age 5 days, before and after iron-dextran. Post-treatment sera had increased inhibitory effects on leucocyte chemotaxis and markedly reduced bacteriostatic effects agaainst E. coli. The clinical relevance of the effects on chemotaxis is uncertain. The reduction in serum bacteriostasis is similar to that observed in other forms of hyperferraemia not associated with saturation of transferrin, and is a likely cause of the increased susceptibility to infection in vivo. We consider that prophylactic treatment with parenteral iron-dextran is contraindicated in early infancy. [ABSTRACT FROM AUTHOR]

Abstract: Dwindling reserves of raw materials in conjunction with the resultant rises in the price of energy and raw materials, serve to emphasise the importance of increasing the energy and material-related efficiency of manufacturing processes. The investigations detailed here, focus on machining processes and illustrate the pivotal importance of tool selection and the associated selection of process parameters to the subsequent energy efficiency of the manufacturing process. A number of processes with a range of target values were investigated on the basis of experimental analyses of drilling into solid material and of cylindrical hard turning processes. The results demonstrate that universally valid criteria relating to the selection of machine tools and parameters in metal cutting processes can initially be set out. There is some potential for further increases in resource efficiency by optimising processes and applications. [Copyright &y& Elsevier]