The functionalization of technical surfaces by microstructuring opens a variety of interesting possibilities, i.e. the generation of stain-resistant surfaces, the specific modification of the tribology of sheet metal ...
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Today's automotive manufacturers are required to meet ever greater demands for increased flexibility due to decreasing batch sizes. Solutions to meet these demands will bring about far-reaching changes to the mass...
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Today's automotive manufacturers are required to meet ever greater demands for increased flexibility due to decreasing batch sizes. Solutions to meet these demands will bring about far-reaching changes to the mass productions methods which currently dominate automotive manufacturing. In addition to the current need for sheet metal components, such trends will also have an effect on assembly and joining techniques used. The paper describes the challenge for production engineering resulting from current and future market demands.
Mechanical Machining of carbide metals is critical, as these materials belong to the hardest substances known. Electrochemical Machining (ECM) is presented as an alternative to conventional processing. This technique ...
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ISBN:
(纸本)0955308224
Mechanical Machining of carbide metals is critical, as these materials belong to the hardest substances known. Electrochemical Machining (ECM) is presented as an alternative to conventional processing. This technique dissolves conductive materials by anodic dissolution in neutral solutions at extremely high current densities of about 100 A/cm. This is independent from the hardness of the work piece and should therefore be favourable to structuring carbide metals. For the reason of carbide metal alloys being composites of extremely hard particles embedded in a softer matrix, ECM of these materials is complex due to the nonhomogenous structure as the components dissolve and passivate differently. The paper starts with results of modifying conventional micro tools made of tungsten carbide. In the second part the potential of working with a free electrolyte jet (EJM) is investigated.
Ultrasonic grinding leads to a reduction of process forces while grinding brittle or hard materials. This effect on the other hand can be used to increase the material removal by increasing the in feed respectively. T...
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ISBN:
(纸本)9781887706421
Ultrasonic grinding leads to a reduction of process forces while grinding brittle or hard materials. This effect on the other hand can be used to increase the material removal by increasing the in feed respectively. To assist good process conditions all components influencing the wave propagation have to be designed in a way that they have a longitudinal eigenfrequency at 20 kHz. To design those components very accurate a systematic and time saving procedure was generated that allows the selection of an optimized geometry out of a multitude of geometries after calculating their dynamic behavior. Therefore, the two software tools Ansys and Matlab were connected with each other to reduce the time-consuming steps while iteratively simulating the eigenparameters. The procedure was validated within multitude investigation at a piezo actor driven test set up.
The use of joinable formed sheet parts made of high-strength and high-tensile materials requires specifically adapted catting technologies to guarantee the requirements for dimensional *** cutting technology used,toge...
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The use of joinable formed sheet parts made of high-strength and high-tensile materials requires specifically adapted catting technologies to guarantee the requirements for dimensional *** cutting technology used,together with the tool and the machine,determine the parameters of the final part,depending on the geometry to be cut and the semi-finished products selected,although the interaction of the workpiece/tribology 、tool system is *** is therefore necessary to modify the tool design for cutting tools in shearing and precision cutting processes and to select appropriate tool materials of steel and ceramics whilst ensuring that the coatings used are sufficiently durable.
In this paper, fundamental investigations on the capabilities of wire electro discharge machining (Wire-EDM) and electrochemical machining (ECM) as suitable pre- and in-process trueing and dressing techniques for fine...
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ISBN:
(纸本)0955308224
In this paper, fundamental investigations on the capabilities of wire electro discharge machining (Wire-EDM) and electrochemical machining (ECM) as suitable pre- and in-process trueing and dressing techniques for fine grained metal bonded diamond grinding wheels are presented. The Wire-EDM process performed on a conventional EDM machine can be used as pre-dressing process for the grinding wheel. Small discharge energies are used in order to realise grit protrusion and to protect smallest diamond grits (10 ìm) of thermal damage. The flexibility of the W-EDM process allows the implementation of virtually any geometry on the grinding wheel. The ECM process performed as a continuous in-process dressing technique keeps a constant grit protrusion during the grinding process. Both dressing techniques can be efficiently combined for grinding small structured geometries with high form accuracy and optical surface quality.
The potential for ultrasonic assisted tools with undefined and defined cutting edges is shown for grinding and turning, whereas the cutting mechanisms are different. Ultrasonic assistance for grinding tools is applied...
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ISBN:
(纸本)9781887706421
The potential for ultrasonic assisted tools with undefined and defined cutting edges is shown for grinding and turning, whereas the cutting mechanisms are different. Ultrasonic assistance for grinding tools is applied to exceed the fracture toughness and thus to induce cracks in the workpiece material. This effect can be used to increase maximum material removal rate or to lower process forces compared to a conventional grinding process at comparable process parameters. Beside the advantages unfortunately the SSD is higher for the ultrasonic assistance which has to be taken into consideration of the process strategy's design. Ultrasonic assistance for ultra-precision turning is applied to decrease the excessive diamond tool wear for ductile machining of hardened steel. The kinematical consideration is the key to achieve appropriate surface conditions as well as reduced tool wear. The investigations show that the conventional parameters like depth of cut a and feed rate f lead to similar results compared to conventional ultra-precision machining. However, a consideration of the kinematical parameters entrance duration ED and entrance speed Vin is likewise mandatory and show the massive influence of the entrance duration ED regarding the surface roughness. Theoretical investigations show also the potential of higher frequencies for the ultrasonic assisted turning process.
Any current assessment of the process outputs, which are derived either by key figures or by process simulation, will not lead to process optimisation, because both the parameters' adjustment and the outputs' ...
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Due to many advantages such as low heat input and high welding speed, laser-welding technology is increasingly used for manufacturing. It is important for the user of laser welding technologies to optimally use the pl...
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Due to many advantages such as low heat input and high welding speed, laser-welding technology is increasingly used for manufacturing. It is important for the user of laser welding technologies to optimally use the plant capacities, to ensure high availability, and to avoid downtimes, rejections and rectifications of rejects. In order to solve the respective problems, the fraunhoferinstitute for machinetools and formingtechnology, in cooperation with Volkswagen Sachsen AG and other partners, is developing a multi-sensor system for in-line process monitoring based upon fuzzy pattern recognition.
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