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Wire-based additive manufacturing represents three of the four processes used to additively manufacture parts at high deposition rates. The three wire-based processes use either electron beam, laser beam, or arc heat sources to melt a wire feedstock, while the fourth high deposition rate process uses directed powders and laser heat sources . High-deposition-rate additive manufacturing (AM) processes tend to use kilowatt (kW) or higher power levels, and can fabricate near-net-shaped parts at kilograms (kg) or multi kg/h build rates with economic advantages over other AM methods (Ref. 5). These processes are distinguished from powder bed AM processes in that they are not confined to a box of prescribed dimensions, they have much higher deposition rates, have little or no restriction in component size, and are more economical in terms of cost per amount of material deposited (Refs. 1-5). Just like powder bed processes, wire-based AM can produce thin wall, thick wall, solid, and/or cast-like components without the need for a die, but with less precision due to the larger amount of material deposited per unit time. Nearly 100% of the wire is incorporated into the final part, making wire-fed technologies a more efficient use of feedstock than powder-based processes (Ref. 4). Components produced by wire-based AM can be compared to castings, but the microstructures are more refined than castings of similar size because the AM liquid weld pool is typically only a few millimeters (mm) in diameter and is often orders of magnitude smaller than the finished part. The refined wire-based AM microstructures have smaller grains, less micro-and macro-segregation, and typically better mechanical properties than castings (Refs. 1, 2, 4). In addition, wire-based AM can be used to build onto, or modify, existing parts through cladding and hardfacing, and can also perform repair and maintenance of castings and other metal parts (Refs. 1-4).The three wire-based AM processes are known by different names in the literature (Refs. 1-3), and will be referred to here as wire-fed laser AM (LAM-W), wire arc AM (WAAM), and wire-fed electron beam AM (EBAM-W [Ref. 6]). Each process uses a different power source, and each has advantages and disadvantages in terms of equipment and operating costs, microstructural control, heat input, surface finish of the part being made, and exposure to atmospheric contamination. Parts produced by the wire-based AM processes have the same nominal composition as the wire being used, with only minor variations in the composition due to different evaporation rates from the liquid weld pool of the various elements in the alloy (Ref. 7) or pickup of atmospheric contaminants (Refs. 8,9). ABSTRACTThree different wire-fed additive manufacturing (AM) processes were employed to evaluate differences between laser, arc, and electron beam heat sources used for highdeposition-rate AM on the order of 1 kg/h. Optimum weld and build parameters were developed independently to match the characteristics of each heat source using 308L...

The stresses developed by five glazes in the field of cone 9 porcelain glazes were determined by the tuning fork method of Blakely. A reaction between the body and glaze at the interface causes a development of stress above the softening point of the glaze. The mat glaze studied showed no crazing even though it was extremely high in tension, whereas a semimat and clear glaze, lower in tension, showed craze marks.