4 research outputs found
Mechanical and physical properties of magnesium alloys prepared by rotary swaging
in english For their positive influence on mechanical and physical properties of the material, methods of severe plastic deformation are popular for quite some time today. Rotary swaging is one of them. With its simplicity and productivity, it has the potential for industrial use. It is a radial swaging of rods or tubes, which results in decreasing of their diameter. Influence of this method is researched on extruded rods made of magnesium alloy AZ31. Experiments are made on five samples of different degree of swaging (different diameter). This allows to research gradual evolution of properties during the swaging. Results show significant positive influence on grain size (and microstructure in general) of originally extruded rod. During swaging there is an evolution of material texture and increase in strength
Anisotropy of thermal expansion in magnesium materials exhibiting texture
Magnesium alloys are valued for their low density and good mechanical pro- perties. Their characteristic is the tendency to obtain a texture during processing, which together with their hcp crystal structure results in the anisotropy of some physical properties. In this work we examine the effect of the texture on the aniso- tropy of thermal expansion of the widely used AZ31 and ZE10 magnesium alloys. These alloys are in the form of thin rolled sheets and we examine them in an as-recieved state and in a condition after an annealing. The measured samples are cut out of the metal sheet in the direction of rolling and in the perpendicular direction. The measurement is carried out in the temperature range from room temperature to 400 â—¦ C. Measuring of the thermal expansion of sheets is problema- tic because they can bend and devalue the measurement results. The result of this work is a confirmation of the existence of this anisotropy and its description.
Anisotropy of thermal expansion in magnesium materials exhibiting texture
v ÄŤeskĂ©m jazyce HořčĂkovĂ© slitiny jsou cenÄ›ny pro svoji nĂzkou hustotu a dobrĂ© mechanickĂ© vlastnosti. Jejich charakteristikou je náchylnost k zĂskávánĂ textury bÄ›hem zpra- covánĂ, která má spoleÄŤnÄ› s jejich hcp krystalovou strukturou za následek ani- zotropii nÄ›kterĂ˝ch fyzikálnĂch vlastnostĂ. V tĂ©to práci zjišťujeme vliv textury na anizotropii teplotnĂ roztaĹľnosti hojnÄ› pouĹľĂvanĂ˝ch hořčĂkovĂ˝ch slitin AZ31 a ZE10. Tyto slitiny jsou ve formÄ› válcovanĂ˝ch plechĹŻ a zkoumáme je ve stavu z vĂ˝roby a ve stavu po urÄŤitĂ©m vyĹľĂhánĂ. MěřenĂ© vzorky jsou z plechu vyĹ™Ăznuty ve smÄ›ru válcovánĂ a ve smÄ›ru kolmĂ©m. Obor teplot, kterĂ˝m jsou vzorky vysta- veny, sahá od pokojovĂ© teploty do 400 â—¦ C. MěřenĂ teplotnĂ roztaĹľnosti plechĹŻ je problematickĂ©, protoĹľe se mohou prohĂ˝bat a znehodnocovat tak vĂ˝sledky měřenĂ. VĂ˝sledkem tĂ©to práce je potvrzenĂ existence tĂ©to anizotropie a jejĂ popis. 1Magnesium alloys are valued for their low density and good mechanical pro- perties. Their characteristic is the tendency to obtain a texture during processing, which together with their hcp crystal structure results in the anisotropy of some physical properties. In this work we examine the effect of the texture on the aniso- tropy of thermal expansion of the widely used AZ31 and ZE10 magnesium alloys. These alloys are in the form of thin rolled sheets and we examine them in an as-recieved state and in a condition after an annealing. The measured samples are cut out of the metal sheet in the direction of rolling and in the perpendicular direction. The measurement is carried out in the temperature range from room temperature to 400 â—¦ C. Measuring of the thermal expansion of sheets is problema- tic because they can bend and devalue the measurement results. The result of this work is a confirmation of the existence of this anisotropy and its description. 1Katedra didaktiky fyzikyDepartment of Physics EducationMatematicko-fyzikálnĂ fakultaFaculty of Mathematics and Physic
Fatigue in an AZ31 Alloy Subjected to Rotary Swaging
The magnesium AZ31 alloy was swaged with rotary pressure with the aim of redefining the microstructure and improving mechanical and fatigue properties. The rotary swaging process and subsequent ageing improved the yield stress in tension and compression. In the present study, the investigation was focused on fatigue behaviour. The samples were cycled in a symmetric regime with a frequency of 35 Hz. A dependence of the stress amplitude on the number of cycles up to the fracture was estimated. The microstructure of the samples and fracture surfaces was analysed with a scanning electron microscope. The fatigue process was influenced by the pronounced texture formed in the swaging process. The fatigue properties of the swaged samples improved substantially—the endurance limit based on 107 cycles was approximately 120 MPa—compared to those of the cast alloy. The analysis of the fracture surfaces showed a transcrystalline fatigue fracture