T. A. Kalashnikova

Structure and tensile fracture of 1570C aluminum alloy

Both deformation and fracture tensile studies on orientation dependence of 1570C aluminum alloys samples with respect to rolling direction have been carried out. As revealed, the viscous fracture mechanism is more inherent to the samples with orientation transversal to the rolling direction while samples oriented along the rolling direction revealed quasi-brittle areas on the fracture surfaces. Despite practically the same level of the yield stress there is 10% difference I the ultimate stress.

Effect of Ultrasonic Application during Friction Stir Welding on Microstructure and Properties of AA2024 Fixed Joints

Microstructure and mechanical properties of aluminum alloy 2024 fixed joint produced by ultrasonic assisted friction stir welding are described. Tensile strength, microhardness, grain size and zone area are measured and compared with ones of joint produced without ultrasonic vibration. Analyzing this data authors make conclusion about ultrasonic vibration effect on friction stir welding joint quality.

Microstructure of Fixed Butt Joints Formed by Friction Stir Welding on 2024T3 Aluminum Alloy

Friction stir welded butt joints on 2024T3 alloy have been obtained using two different process regimes. The microstructures of all the weld joint zones have been examined and such structural parameters as grain size, particle size and volume content of particles have been determined in order to find correlations with the microhardness of the corresponding zones.

Towards the problem of forming full strength welded joints on aluminum alloy sheets. Part II: AA7475

The microstructural evolution in welded joint zones obtained both by friction stir welding and ultrasonic– assisted friction stir welding on dispersion hardened 7475 aluminum alloy has been examined together with the analysis of mechanical strength and microhardness. It was established that ultrasonic-assisted friction stir provided leveled microhardness profiles across the weld zones as well as higher joint strength as compared to those of standard friction stir welding.

AA2024 microstructural evolution after bidirectional friction stir processing

The microstructure of AA2024 sheet subjected to the multiple pass bidirectional friction stir processing (FSP) was studied. The experiments demonstrated the structural homogeneity of metal on the intersections between two perpendicular passes. The FSP process parameters suffer dramatic changes on the intersections as compared to those when processing the base metal. The FSP tool travel resistance is reduced when encountering the previously stirred metal due to different conditions of deformation and the tool-induced metal flow existing in the structurally modified stirring zones.

Friction-stir processed ultrafine grain high-strength Al-Mg alloy material

It was shown experimentally that both friction stir processing parameters and the workpiece thickness have their effect on structure and mechanical properties of the processed samples. Even the 10% deflection from the optimal values resulted in the essential mechanical strength reduction. It was observed that FSP showed a tendency to suppress the serrated yielding during the tensile testing.

High-strength friction stir processed dispersion hardened Al-Cu-Mg alloy

It was experimentally shown that optimal friction stir processing (FSP) parameters existed for Al-Cu-Mg alloy samples subjected to friction stir processing in the sense of obtained ultrafine metal strength and microstructure. FSP of this alloy resulted in the formation of a recrystallized grain zone. The deflection from optimal process parameters resulted in lower FSPed metal strength.

Orientation dependence of compression deformation on 1570C aluminum alloy

The compression deformation orientation dependence of Al-Mg-Sc-Zr aluminium alloy has been studied. As shown, the compression axis orientation with respect to previous rolling direction changes the stress-strain curve behavior. The discontinuous yielding during compression deformation along the rolling direction of characterized by two types of serrations as compared to the only one type in case of deformation transversal to the rolling direction.

Microstructure of AA 2024 fixed joints formed by friction stir welding

Friction stir welded butt joints on 2024T3 alloy have been obtained using different process parameters. The microstructures of all the weld joint zones have been examined and such structural parameters as grain size, particle size and volume content of particles have been determined in order to find correlations with the microhardness of the corresponding zones of the weld.