THE INFLUENCE OF TOTALL ROLLING REDUCTION FOR UNEVENNESS OF STRAIN OF THREE-LAYER PLATES

WPŁYW GNIOTU CAŁKOWITEGO NA NIERÓWNOMIERNOŚĆ ODKSZTAŁCENIA WARSTW BLACHY TRÓJWARSTWOWEJ

PIotr Murawski, Nina Torbus, Dariusz Rydz

Czestochowa University of TechnologyFaculty of Materials Processing Technology and Applied Physics, Institute of Modeling and Automation of Plastic Working Processes

 

Słowa kluczowe:Blachy trójwarstwowe, modelowanie numeryczne, walcowanie, MES.

Key words: three-layer bimetallic plates, numerical modeling, rolling process, FEM.

 

In the article the analysis of deformation in the rolling gap during the asymmetric rolling process and thickness of each layer of multilayer plates was showed.

The paper presents the numerical modeling of the process of rolling a three-layer bimetallic plate composed of non-ferrous metals. Three-layer plates (M1E - Al99,8 - AlMg5 – according to polish standards) connected with the use of explosive welding where used for researches. The proposed group of materials is a combination of copper and a layer of aluminum alloys with magnesium, whose direct connection without the use of the explosive welding method is impossible due to their properties.

The results of theoretical research with using FEM software Forge®, which enables to make computer simulations in 3D state of deformation were showed. A computer program Forge 2008® has been used in the research, whose calculations are based on the finite element method. Geometry of initial materials and tools were prepared in Rhinoceros 4.0® program and for generation of mesh elements the Preprocess of Forge2008® was used. For the mesh creation the tetrahedron finite element method was used. The mesh was generated separately for each layers. Computer tests were performed for three values of relative rolling reduction e = 10%, 15% and 20% at the temperature t = 20°C. The variables set to perform computer simulations for the process of rolling trimetal plates were: The ratio of the cylinder radius (h / R = 0.1, 0.2, 0.4) and the ratio of thickness of the layers constituing trimetal (hAlMg5./hAl99,8./hM1E).
In order to analyze the thickness of each layer of trimetallic plate, measurements of thickness in the Postprocess of Forge2008®, has been performed. The results of measurements of the total thickness and the thickness of individual layers of the test samples are presented in the table. Individual results are arithmetic average of six measurements for each sample.

BILAYERS Ni/Cr ON THE COPPER

RECEIVED BY ELECTROCHEMICAL METHOD

Ganna Kulakovska, Monika Gwoździk, Swietlana Pietruszczak, Prof. Zygmunt Nitkiewicz

Czestochowa University of Technology, Faculty of Materials Processing Technology
and Applied PhysicsInstitute of Material Science

Key words:electrolytic layers, bilayer, diffusion, heat-treatment

Abstract

Electrolytic layers applied to metals and their alloys have long been used in order to improve their properties. However, the obtained layers do not always meet the expected properties of such layers with high resistance usually peel off due to poor adhesion of the layer to the base material. The layers with high adhesion to the base material typically have low strength.

In order to remove such defects there are numerous attempts made to carry out additional hardening treatment involving the application of different heat treatments.

In the case of electrolytic layers (used in both chromium and nickel on the copper) there are casting machines used in cyclic heat treatment which is carried out at 350°C. Using this type of treatment makes it possible to achieve high strength properties of both layers nickel and chromium but with low adherence. However carrying out heat treatment at higher temperatures (950-1000°C) leads to a reduction in mechanical properties of such layers. In these types of layers it was impossible to obtain a diffusion layer, since the element chromium is insoluble in copper, in turn, produced a layer of nickel on copper that is characterized by a lack of adhesion to the base material.

The solution of this problem can be made by plotting a double layer (bilayer) of Ni/Cr on the copper. According to the literature, nickel and copper have unlimited dissolve of each other and chromium has a high level of dissolve in steady solute produced by nickel and copper.

This project analyzed the effect of heat treatment on the properties of bilayer Ni/Cr plotted on the copper. Electrolytic bilayer obtained by heat-treatment relied on annealing at 950 ° C with cooling both the air and the furnace. The impact of heat treatment on diffusion processes occurring in the metal used and the effect of cooling speed on the course of diffusion was analyzed.