SEARCH RESULT

In this study, the (hkl) plane energies of bcc and bct Fe crystals were calculated as a function of internal interactions between atoms. The Classical Morse Potential Function applied in the theoretical studies of transition elements was used in Fortran code for analytical calculations. Since the force applied to the crystal at the equilibrium has bcc → bct conversion, we calculated the variations of the a2 lattice parameter depending on the a1 lattice parameter. The (hkl) plane energies of bcc and bct crystals were determined using calculated lattice parameters. Calculations are limited to 9 (hkl) planes. For the bcc Fe (h00) planes, the internal energy passed through the minimum points, while the energy in the (hk0) and (hkl) planes changed parabolically. In the case of bct, no stability point was determined on any plane. Theoretical calculations show that the total energy is the nearest plane energy of the incoming feeds. In bcc → bct phase transformation, the system has a single equilibrium point and the stability range is not very large. This calculation method can be successfully applied to cubic Fe and Fe-based alloys in the theoretical studies.

International Iron & Steel Symposium
UDCS

Hamza Yaşar Ocak Gökay UĞUR Şule UĞUR

Because Al-Sc alloys are used extensively in the industry due to their many properties, both theoretical and experimental researchers are interested. The importance to these alloys is the physical and chemical properties they exhibit at lower proportions of Sc additives. We also obtained Al-1.1Sc and Al-1.9Sc alloys using a special method. By doing XRD analyzes at room temperature, we reached the conclusion that both alloys crystallized in the same 225 space group and fcc structure. We calculated the second-order elastic constants using the knitting parameters obtained from the EMTO program. In this study, by using XRD test results and theoretical calculation results; (hkl) in the crystal planes defined by Miller indices; peak widths, crystal dimensions, dislocation densities, Young's constants and Maximum Stresses were examined separately. It is seen that the physical parameters (hkl) change according to their planes in the result of the study done. In particular, the maximum stress and Young's modulus were found to be mechanically better for the strength of the Al-1.1Sc alloy.

International Symposium on Light Alloys and Composite Materials
UHAKS

Hamza Yaşar Ocak Rahmi Ünal Gencer Sarıoğlu Şule Uğur Gökay Uğur

Al-Sc Alloys have an important use area due to their strength and lightness in automotive and space industry. Al- 1.1Sc and Al-1.9Sc alloys were obtained by a special method. The sample preparations and measurements required for the test measurements were made at the advanced technology center (ILTEM-DPU). First, the hardness of these alloys was measured experimentally by Vickers hardness measurement (Duroline-M). X-ray analyzes of the samples were obtained at room temperature with the Panalytical-Empyrean (XRD) model. The XRD results were theoretically analyzed according to the Debye - Scherrer method according to the hardness variations (hkl) planes. In both studies, it was observed that the hardness of Al-1.9Sc alloy is high. According to this; Al-Sc alloys have reached the conclusion that the increasing proportion of Sc has increased rigidity.

International Symposium on Light Alloys and Composite Materials
UHAKS

Gencer Sarıoğlu Hamza Yaşar Ocak Reyhan Başar

To calculate the anisotropies of Al-Sc alloys under high pressure, second order elastic constants obtained using density functional theory calculations implemented in WIEN2K software package. Elastic constants of cubic fcc Al-1.1Sc and Al-1.9Sc alloys obtained as a function of pressure. Elastic constants of both alloys were observed to have subtantially changed with pressure. Pressure based elastic constats were used to calculate the elastic anisotropy (A) and anistropy (ACNNF) that was used to define the center next nearest exhange correlation parameters. It was observed that both anisotropy parameters were changed according to Sc content and pressure. And at increasing values of pressure they approach each other. What makes this study speacial is that this is the first time that anistropies of Al-Sc alloys as function of pressure is investigated.

International Symposium on Light Alloys and Composite Materials
UHAKS

Hamza Yaşar Ocak Gencer Sarıoğlu Salih Akbudak Gökay Uğur Şule Uğur