Thermal/cold spray deposition were used for additive manufacture of oxide dispersion strengthened (ODS) steel layers. Mechanically alloyed F/M ODS steel powders (Fe(bal.)-10Cr-1Mo-0.25Ti-0.35Y2O3 in wt.%) were sprayed by a high velocity oxygen fuel (HVOF) and cold spray methods. HVOF, as a thermal method, was used for manufacturing a 1 mm-thick ODS steel layer with a ~95% density. The source to objective distance (SOD) and feeding rate were controlled to achieve sound manufacturing. Y2Ti2O7 nano-particles were preserved in the HVOF sprayed layer; however, unexpected Cr2O3 phases were frequently observed at the boundary area of the powders. A cold spray was used for manufacturing the Cr2O3-free layer and showed great feasibility. The density and yield of the cold spray were roughly 80% and 45%, respectively. The softening of ODS powders before the cold spray was conducted using a tube furnace of up to 1200°C. Microstructural characteristics of the cold sprayed layer were investigated by electron back-scattered diffraction (EBSD), the uniformity of deformation amount inside powders was observed.
Mortar feedstock is extruded to form bead and it is selectively placed line by line in the material extrusion additive manufacturing. With respects to part building process healthiness, load-supporting ability of overlaid beads is emphasized as buildability. Buildability is primarily dependent on thixotropic properties of feedstock and vertical overlapping schedule. In the present study, water-to-binder (w/b) ratio was chosen as material aspect to assess buildability. Uneven bead shape evolution and premature failure were highlighted owing to low yield stress of high w/b ratio feedstock. Feedstock with optimum w/b ratio showed good buildability even at the interval time of 19 sec.
Article presents results of laser overlaying welding of metal powder Inconel 625. Laser metal deposition by laser engineered net shaping (LENS) is modern manufacturing process for low scale production series. High alloy materials such as Inconel 625 nickel based super alloy have high thermal resistant and good mechanical properties, nevertheless it's hard to machining. Plastic forming of high alloy materials such as Inconel 625 are difficult. Due to high strength characteristic performing components made from Inconel alloy are complex, selective melting of metallic powder using laser beam are alternative method for Inconel tooling. Paper present research of additive deposition of spatial structure made from Inconel 625 metallic powder with CO2 laser and integrated powder feeder. Microstructure analysis as well as strength characteristic in normal condition and at elevated temperature was performed. Possibility of using LENS technology for manufacturing components dedicated for work in high temperature conditions are presented.