Papers by Keyword: Combined Process

Abstract: The combination of the conventional forming processes rolling and extruding enables the continuous production of cross-sectional aluminum long products. Regarding power consumption and resulting material specifications, the combined process offers various advantages in comparison to its conventional alternatives [1, 2]. The combined rolling and extrusion process is in an early stage of maturity. The production of pure aluminum wire is state of the art. The material flow within the process can partially reproduced by the use of numerical simulations [3]. Some process specific characteristics need to be understood and controlled to obtain a better process design and to enable the future production of complex cross-sectional products. This paper describes the results of experimental and numerical investigations regarding the combined rolling and extrusion process. The test specimen of a visioplastic examination on an industrial scale plant [3] was examined by the use of metallography. Those results where compared to a numerical simulation of the industrial experiment. The comparison of these results where then linked to some specific characteristics of the process. The existence of a dead zone with a shape comparable to the conventional indirect extrusion process was proved. The deformation zone of the combined process was divided into four zones which can be differentiated in the experimental as well as the numerical results. General design rules were derived from this differentiation. These design rules were used to optimize the forming geometry of an industrial scale plant. Critical process forces where reduces and resulting scrap material was minimized.

Abstract: The article is devoted to the study of energy-force parameters of combined process "rolling-equal-channel angular pressing". The objectives of the work were to determine the forces of rolling and pressing in the deformation by this combined method. The strength calculation of the matrix and the experiment on deformation of AISI 6063 aluminum samples were carried out. During the experiment, the force values were recorded using a tensometric station. The results of the strength analysis showed that this matrix design is suitable for creating an experimental stand of combined process "rolling – equal-channel angular pressing", since the calculated safety margin is sufficient to implement the pressing under extreme conditions. Analysis of the results of force measurement showed that rolling forces at all stages of deformation exceed the corresponding pressing forces, which is a necessary condition for the implementation of this combined process. The obtained results can be used in the design of experimental stands that implement investigated combined process. At the same time, the used tensometric technique for studying strength characteristics is suitable for the case of calibrated rolls.

Abstract: In recent years was developed a number of new methods of processing of metals by pressure aimed at obtaining metal with sub-ultrafine-grained structure, the basic principle of which is the realization in the process of deformation of simple shear scheme. One of those ways is pressing blanks in matrices of different designs, in particular in equal-channel step die. However, this method has a significant disadvantage - it can’t be used for deforming of lengthy billets. Another disadvantage of this method of deformation is that it does not provide the continuity of the pressing process. For removing these shortcomings at the Department "Metal Forming" of Karaganda state industrial University was developed a combined process "Rolling-pressing" using equal channel step matrix with calibrated and smooth rolls. This work investigates the impact of the proposed combined process "rolling-pressing", and also preliminary and final heat treatment during the implementation of this combined process on the evolution of microstructure and mechanical properties of copper alloy. Obtained in the course of these studies, the results indicate that the proposed technology can be recommended for implementation in production to produce blanks of ferrous and non-ferrous metals and alloys with ultrafine-grained structure and high level of mechanical properties.

Abstract: In this work a simulation of the innovation process "helical rolling – pressing" in the software package Simufact.Formingwas performed. The result is several models of this process. To analyze the feasibility of the process various key parameters that have a significant impact on the implementation processwere carried out. As a result, the optimal values of friction coefficients in the rolls and in the matrix, the angle of intersection of channels in the matrix and the distance of matrix from the deformation zone of the rollswere obtained.

Abstract: In this paper was considered a qualimetric evaluation of aluminum wire deformed by a combined scheme of deformation “pressing-drawing”. Comparative analysis of complex quality indicators of deformed aluminium wire in different technologies has proved the advantage of the new technology for the production of wire compared with the existing technology.

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Abstract: A representative gold ore sample subjected in this work was taken from Guangnan gold mine, Wenshan municipality, Yunnan province, China. The ore sample assays 2.21 g/t Au, and the gold element exists in oxides, sulfides and silicates. Detailed tests as flotation and leaching were conducted in order to make good use of the valuable element. A flotation concentrate which assays 19.48 g/t Au is obtained through a flotation process of one rougher, two scavengers and two cleaners under the grinding fineness of 90% -0.074mm. The flotation concentrate with rich Au content is a high quality feed for metallurgy. And the flotation tailings were subjected to leaching. After 24 hours, the leaching rate reaches 90%.

Abstract: A novel hydrorefining/hydroupgrading/hydrodewaxing combined process for clean, low freezing diesel production were studied in this paper. the catalytic performance of three hydrorefining/hydroupgrading/hydrodewaxing combined catalysts were examined on 200mL hydrogenation units using the same feedstocks, the results revealed that the sulfur contents of diesel product were less than 50μg·g^-1,and all the three combined catalysts can produce-20# diesel, and HU-1 catalyst had the better hydroupgrading performance than HU-2 catalyst.

Abstract: Research on removing algae in slightly polluted Yellow River water using four combined processes , compared the effect in removing algae of every combined process , It will provide a reference for the profess of treatment drinking water using Yellow River water as headwaters for the future.

Abstract: It is difficult to handle platinum-palladium ores in Jinbaoshan due to low grade ores, kinds of mineral resources, complex mineral structure, fine-grained dissemination, which is a typical refractory complex ores. Based on the research of lots of correlative literature, this article analyses refractory reasons of platinum-palladium ores in Jinbaoshan, and provides an overview of comprehensive utilization status of low grade and refractory platinum-palladium ores on behalf of single flotation process, stage grinding-stage sorting and the combined process of flotation and magnetic separation, microwave pretreatment-leaching-replacement process, and the activation of acid leaching-extracting magnesium and iron-leaching residue to flotation process and so on.