Mykhailo Stolbchenko

Twin‐Roll Casting of Carbon Fiber‐Reinforced and Glass Fiber‐Reinforced Aluminum Strips

The modern requirements for lightweight products force one to make constructional materials with brand new properties. One such group of materials that meets these demands are fiber-reinforced metal-matrix composites. A combination of light and good deformable aluminum with a strong fiber allows obtaining high strength, ductility and corrosion resistance in a single product. In the present article the application of energy-efficient technology of twin-roll casting for production of flat aluminum-matrix composites reinforced with carbon and glass fiber is observed. The corresponding experimental study on the manufacturing of thin strips of pure aluminum reinforced with carbon and glass fiber rovings was carried out using a 370 mm roll diameter labor twin-roll caster. The obtained flat products of 3…5 mm thickness were analyzed by means of mechanical tests and electron microscopy. The results have shown a great potential of the twin-roll casting for production of high-strength fiber-reinforced aluminum strips.

Influence of surface roughness on the bonding quality in twin-roll cast clad strip

ABSTRACT Manufacturing of aluminum-steel clad strips by means of twin-roll casting is of great interest due to a shorter production chain in comparison with convenient technologies. Experiments on twin-roll casting of clad strips of pure aluminum and an austenitic stainless steel of 2.5 mm total thickness with the inline abrasive cleaning of a steel substrate’s surface performed. The corresponding device for the inline surface preparation is designed. The influence of surface roughness of the substrate’s surface on the bonding strength between strip layers is analyzed. The mechanism of intermetallic bonding on the roughened surfaces is discussed. It is shown that surface roughness of steel substrate up to 4.2 µm provides bonding strength above 100 MPa.

Asymmetric Twin-Roll Casting of an Al-Mg-Si-Alloy

The industrial application of high-alloyed Al-Mg-Si alloys for the production of thin strips by means of twin-roll casting is limited due to the structural inhomogeneity and segregation formation. To reach the highest mechanical properties of the finished product, a direct influence on the strip formation conditions during the twin-roll casting can be applied. Analogous to the asymmetric rolling process, additional shear stresses were created in the strip forming zone by using different circumferential velocities and torques of the caster rolls. To provide the asymmetric process conditions, only one caster roll was left driven and the second one was left idling during the casting process. The microstructure and the mechanical properties of the strips in the as-cast state as well as after the homogenization and subsequent age-hardening were analyzed. A comparison of the test results showed a positive influence of the asymmetry conditions on the strips’ properties.

Twin-Roll Casting of Aluminum-Steel Clad Strips: Static and Dynamic Mechanical Properties of the Composite

The manufacturing of thin aluminium-steel clad strips by means of twin-roll casting is a prospective trend of the progress in the light metals sheet production. The resulting composite possesses high bonding strength due to the presence of a continuous thin layer of intermetallic phases at the bonding interface of metallic constituents. At the same time, for the application of twin-roll cast clads, the evaluation of their properties is of great importance. In order to determine the behavior of twin-roll cast aluminum-steel clad strips under loading, monotonic tensile and fatigue tests were carried out. Therefore, strips in the as-cast condition as well as after a heat treatment, stimulating the growth of the intermetallic phases, were subject for the characterization. In addition, the specimen’s fracture surfaces were analyzed using scanning electron microscopy to obtain information on the type of fracture, the location and source of the crack nuclei.

Rolling of Flat Aluminum Strips with Tailored Mechanical Properties

In this study, the possibility of producing of flat aluminum strips with tailored mechanical properties across their width by means of rolling was examined. The aim of the work was an experimental analysis of the effect of cold rolling of the strips with a pre-profiled cross-section in flat rolls. Because of different work hardening of the various elements of the pre-profiled strips a characteristic profile of mechanical properties over the strips cross-section was created. The performed tensile tests and hardness measurements proved the possibility of setting of tailored properties in flat strips by means of rolling. The difference between the mechanical characteristics of various strip’s elements for the selected aluminum alloy can reach 40%.