The paper presents the results of the experimental tests of Mg/Al bimetallic bars rolling process in classic and multi-radial modified round-oval-round passes. The bimetallic bar consist of magnesium core, grade AZ31 and aluminium outer layer, grade 1050A. The stocks were round bars with diameter 22.5 mm with an aluminium layer share of 28%. As a result of rolling in four passes, bars of a diameter of about 17 mm were obtained. A bimetallic feedstock was manufactured using an explosive welding method. The use of the designed arrangement of multi-radial modified stretching passes resulted in obtaining Mg/Al bimetallic bars with an uniform distribution of the cladding layer over the bar perimeter and high quality of shear strength between individual layers compared to Mg/Al bars obtained in the classic passes.
The present paper reports the results of theoretical and experimental studies of the process of die forging a bimetallic door handle intended for the production of a helicopter. The aim of the studies was to develop and implement a technology for die forging of a product with a specific mass similar to that of magnesium alloys which will have, however higher corrosion resistance. Numerical modelling and industrial tests were carried out based on the previously forging processes for an AZ31 alloy door handle. The material for the tests was a bimetallic bar produced by the explosive welding method, in which the core was of alloy AZ31, and the cladding layer was made of 1050A grade aluminium. The studies were conducted for two variants: Variant I – the forging process was mapped by numerical modelling and industrial tests for the die shape and parameters used in the forging of the AZ31 alloy door handle, Variant II – the tool shape was optimized and process parameters were selected so as to obtain a finished product characterized by a continuous Al layer. From the theoretical studies and experimental tests carried out it has been found that the application of the Variant I does not assure that a finished door handle characterized by a continuous cladding layer will be produced. Within this study, a novel method of bimetallic door handle die forging (Variant II) has been developed, which limits the amount of the flash formed and assures the integrity of the cladding layer.
Boron nitride thin layers were produced by means of the pulsed laser deposition technique from hexagonal boron nitride target. Two types of laser i.e. Nd:YAG with Q-switch as well as KrF coupled with RF generator were used. Influence of deposition parameters on surface morphology, phase composition as well as mechanical properties is discussed. Results obtained using Fourier Transformed Infrared Spectroscopy, Transmission and Scanning Electron Microscopy, Atomic Force Microscopy are presented. Micromechanical properties measured during microindentation, scratch and wear tests are also shown.
The paper has presented the results of theoretical studies and experimental tests of the plastic deformation of multi-layered Ti/Al/Mg specimens. Theoretical studies were carried out using the Forge2011® computer program. Physical modeling, on the other hand, was performed using the Gleeble3800 simulator. Cuboidal specimens were cut off from the plates obtained in the explosive welding method. Based on the obtained investigation results it has been found non uniform deformation of the particular layer as a result their different value of flow stress.