R. Kowal

Study of the Structural Properties and Segregation of Alloying Elements in Strips from the TRC Line

Twin roll casting (TRC) technology is becoming increasingly popular because of the opportunity to receive aluminum strips which may serve as input for direct cold rolling processes. Furthermore, these strips have a favourable combination of mechanical and electric properties as well as dimensional tolerances. TRC line strips show segregation of alloying elements and structure providing a combination of casting structure and wrought alloy. As part of this study, the structure of the strips from the TRC line has been analyzed as well as the segregation of the alloying elements.

New Type of Lightweight Railway Overhead Line Carrying Equipment

Traditional carrying equipment that is being still used in polish railway system for dozens of years is based on typical steel profiles with low mechanical strength, low corrosion resistance and also with poor assembly and adjustment possibilities. Major part of other overhead railway equipment like support constructions, trolley wires and current carrying equipment is now modernized leaving the carrying system one of the lasts that needs to be redesigned and optimized to meet nowadays requirements for high speeds of railway travel. For that direct reason a project was started to conduct research works on design and development of the new type of railway overhead carrying equipment with enhanced exploitation properties. Within this articles authors presented a complete set of research results including designing of first concepts, FEM simulation and experimental research results including tests on final geometries in actual railway traffic. Performed studies and design works allowed to obtain an innovative overhead railway carrying system which is based on 6082 aluminum alloy and new geometry of used profiles and connection system. Research results conducted and presented within article are a part of the project co-founded by The National Centre for Research and Development.

New Aluminum Base Materials for Use on Electrical Purposes

Modern power industry expects new, dedicated aluminum based alloys with non-standard properties, including increased resistance to temperature. Materials exhibiting higher thermal resistance allow to increase operating temperature of electrical conductors, which results in the increase of their current carrying capacity. Commonly known and used in such applications are alloys from the AlZr group. Despite their advantages scientists from around the world are searching for new alternatives. In this paper authors present research results on Al-Mo and Al-Ag alloys with particular interest to the analysis of the molybdenum addition to the aluminum in the amount of 0.05, 0.1, 0.2% and silver addition in the amount of 0.05, 0.1, 0.15% by mass on the mechanical and electrical properties of obtained alloys. Tests were also carried out for reference material which is high-purity aluminum and the AlZr alloy, both in the as cast state temper. Results showed a significant change of temperature coefficient of resistance in Al-Ag alloys compared to Al, which leads to possible increase of the Joule’a heat without the raise of conductors temperature limit. On the other hand, above-average heat resistance of alloys from the Al-Mo group of materials was achieved during the trials. On that basis authors state that Al-Ag alloys may be used for the production of ACSS conductors and Al-Mo alloys for TACSR or TACIR type of conductors.This study was performed under a project financed by NCBiR within the INNOTECH II program.

Influence of Continuous Casting Conditions on Segregation of Additions in EN AW 1350 Aluminum Alloy

Integrated continuous casting processes are an important element of the production process in modern industry. Requirements for quality and exploitation properties of products obtained using continuous casting processes necessitate a revision of the role of impurities distribution in the material. This paper concerns on the influence of the casting process on the distribution of alloy additions. Spectroscopy studies were performed for the most sensitive elements, from the segregation, (i.e. : iron and silicon) point of view. Next obtained research results were correlated with the parameters of chemical composition such as casting speed, the presence of a modifier and the processing of metal crystallization zone. Analysis of the results clearly shows the presence of iron and silicon normal macrosegregation. It was observed that the concentration of these elements is highest in the casting axis and, in the case of iron, is 50% higher in the axis than in the circumference of casts.