Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : ray diffraction

Formation of Compressive Residual Stresses by Shot Peening for Spot Welded Stainless Steel Plates

Ali H. Fahem; Samir Ali Al-Rabii; Ahmed Naif Al-Khazraji

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2198-2211

In this paper, a stainless steel 316 was selected for this study and tested to obtain its chemical composition, mechanical properties and stress relieving. Then, two plates (55*55*1) mm were first joined by spot welding and later tested by X-Ray diffraction (XRD) machine to measure the tensile residual stresses formed due to thermal effect. In order to remove the tensile residual stresses, a shot peening process for these spot welded plates was made to create the compressive residual stresses which will improve the life of spot welded part during the service. The results of the x-ray diffraction tests exhibited that only compressive residual stresses formed in the shot peened spot welded plates.

Characteristics of Nanostructure Porous Silicon Prepared by Anodization Technique

Ayoub H. Jaafar; Uday M. Nayef

Engineering and Technology Journal, 2013, Volume 31, Issue 3, Pages 339-347

Porous silicon (PS) layers are prepared by anodization for different current densities. The samples are then characterized the nanocrystalline porous silicon layer by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR), Reflectivity and Raman. PS layers were formed on a p-type Si wafer. anodized electrically with a 10 and 40 mA/cm2 current density for fixed 20 min etching times.
We have estimated crystallites size from X-Ray diffraction about nanoscale for porous silicon and AFM confirms the nanometric size and therefore optical properties about nanocrystalline silicon yields a Raman spectrum showing a broadened peak shifted below 520 cm-1.