Metal additive manufacturing has employed several technologies and processes to advance from rapid prototyping to rapid manufacturing. Additive manufacturing technologies compete with traditional manufacturing methods through their ability to produce complex structures and customized products. This paper aims to study the characteristics of stainless steel 316L (UNS S31603) parts produced using a selective laser melting machine. In the aerospace industry, turbine blades are typically manufactured from nickel-based alloys, titanium alloys, and stainless steels. Several geometries typical of airfoil blades were examined. The main goal is to investigate the material characteristics and surface features of the airfoil blades. The study included the geometrical errors, surface microstructures, material compositions, material phases, and residual stresses of the samples produced. The characteristics of the parts produced were investigated based on experimental observations. The paper also discusses the influence of the part dimension and orientation on the profile error, surface microstructure, and residual stress.

On the characterization of stainless steel 316L parts produced by selective laser melting

In carbide cermet coatings, such as WC–Co–Cr, the surface roughness of the sprayed workpiece is much more than the acceptable values for various industrial demands. Thus, the surface of the carbide cermet coatings is to be ground appropriately to obtain suitable surface finish. However, the grinding may change the properties of coating. In this study, effects of the grinding process on the porosity content, residual stress, microhardness, and adhesion and cohesion strength of the high-velocity oxy-fuel WC–10Co–4Cr coatings are investigated. For this purpose, the grinding experiments have been performed on a surface grinder using a diamond wheel (resin bond) under different grinding parameters, such as table feed rate, cutting speed, and depth of cut. The investigations of residual stress state and adhesion properties were carried out using the X-ray diffraction and interfacial indentation test methods, respectively. The results indicated that the coating's porosity content increased after grinding due to ...

Effect of Grinding on the Residual Stress and Adhesion Strength of HVOF Thermally Sprayed WC–10Co–4Cr Coating

Through-thickness distributions of residual stresses were determined in an 80-mm thick ferritic steel weld using neutron diffraction and contour method. A two- wavelength (1.55 and 2.39 A ˚ ) combined method, which is based on minimized cross-section and attenuation, enables us to measure residual stresses in such a thick specimen using neutron diffraction. Moreover, the results were complemented by contour method destructively. Signifi- cant tensile longitudinal stresses (up to 660 MPa approaching the yield strength) occur along the weld cen- terline within 10 mm from the top surface, while compressive transverse stresses (about −100 MPa) were found near the weld mid-thickness. Grain size, hardness, and charpy impact energy were further examined to sug- gest a critical location of fracture associated with residual stresses.

Through-thickness distributions of residual stresses in an 80 mm thick weld using neutron diffraction and contour method

Among the various Additive Manufacturing (AM) technologies available for metal part production, powder bed processes are the most promising for industrial mass production. However, one obstacle to ...

Residual stress analysis of thin AlSi10Mg parts produced by Laser Powder Bed Fusion

Until the past few years, failure of flexible devices has mostly been studied through performance tests or durability tests under cyclic loading but as they rapidly grow into mainstream products it has become mandatory to find the underlying reasons resulting in their failure towards fabrication of reliable and longer lasting devices. Failure of flexible devices can be attributed to either failure of individual layers or interface failure. This article covers characterization techniques for measuring interfacial adhesion and mechanical properties of thin films, specifically those on flexible substrates.

Gary S. Schajer

Papers

Practical Residual Stress Measurement Methods: Schajer/Practical Residual Stress Measurement Methods