Effects of Laser-Beam Defocus on Microstructural Features of Compositionally Graded WC/Co-Alloy Composites Additively Manufactured by Multi-Beam Laser Directed Energy Deposition.

Title Effects of Laser-Beam Defocus on Microstructural Features of Compositionally Graded WC/Co-Alloy Composites Additively Manufactured by Multi-Beam Laser Directed Energy Deposition.
Authors T. Kunimine; R. Miyazaki; Y. Yamashita; Y. Funada
Journal Sci Rep
DOI 10.1038/s41598-020-65429-8
Abstract

Establishing processing routes for obtaining metal-matrix composites (MMCs) with uniformly-dispersed reinforcements is one of the main subjects in additively manufactured composite materials to achieve designed microstructures and mechanical properties. Here we report on the microstructural features of compositionally graded WC/Co-alloy composites additively manufactured by multi-beam laser directed energy deposition (multi-beam LDED). For tailoring microstructures of compositionally graded WC/Co-alloy composites with uniformly-dispersed reinforcements, the combinational method: the laser-beam defocus function in the multi-beam LDED system and granulated powder was attempted. By laser defocusing in the multi-beam LDED system, composites with uniformly-dispersed WC particles in Co alloy matrix was successfully obtained due to melting of Co bond in WC-12?wt.%Co granulated particles. It was found that the laser defocusing of multi-beam lasers affects temperature increase of flying powder during the laser focusing area, resulting in change of processing mode from melt-pool mode to thermal spray mode. The preferable property gradients in the WC/Co-alloy composites could be obtained by controlling the feeding rate of the powders and laser-beam defocus. These experimental results demonstrated the effectiveness of the laser-beam-defocus function in the multi-beam LDED system as a key factor for tailoring microstructures of additively-manufactured functionally graded MMCs with uniformly-dispersed reinforcements.

Citation T. Kunimine; R. Miyazaki; Y. Yamashita; Y. Funada.Effects of Laser-Beam Defocus on Microstructural Features of Compositionally Graded WC/Co-Alloy Composites Additively Manufactured by Multi-Beam Laser Directed Energy Deposition.. Sci Rep. 2020;10(1):8975. doi:10.1038/s41598-020-65429-8

Related Elements

Cobalt

See more Cobalt products. Cobalt (atomic symbol: Co, atomic number: 27) is a Block D, Group 9, Period 4 element with an atomic weight of 58.933195. Cobalt Bohr ModelThe number of electrons in each of cobalt's shells is 2, 8, 15, 2 and its electron configuration is [Ar]3d7 4s2. The cobalt atom has a radius of 125 pm and a Van der Waals radius of 192 pm. Cobalt was first discovered by George Brandt in 1732. In its elemental form, cobalt has a lustrous gray appearance. Cobalt is found in cobaltite, erythrite, glaucodot and skutterudite ores. Elemental CobaltCobalt produces brilliant blue pigments which have been used since ancient times to color paint and glass. Cobalt is a ferromagnetic metal and is used primarily in the production of magnetic and high-strength superalloys. Co-60, a commercially important radioisotope, is useful as a radioactive tracer and gamma ray source. The origin of the word Cobalt comes from the German word "Kobalt" or "Kobold," which translates as "goblin," "elf" or "evil spirit.

Tungsten

See more Tungsten products. Tungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f14 5d4 6s2. Tungsten Bohr ModelThe tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance. Elemental TungstenTungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO4) and wolframite [(Fe,Mn)WO4]. In reference to its density, Tungsten gets its name from the Swedish words tung and sten, meaning heavy stone.

Related Forms & Applications