Influence of laser power and powder feed rate on the microstructure evolution of laser metal deposited Ti-5553 on forged substrates
Autor: | Paul Blackwell, C. Hicks, Tatyana Konkova |
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Rok vydání: | 2020 |
Předmět: |
010302 applied physics
Equiaxed crystals Materials science Scanning electron microscope Mechanical Engineering 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Laser Microstructure TS 01 natural sciences Grain size law.invention Mechanics of Materials law 0103 physical sciences General Materials Science TJ Laser power scaling Texture (crystalline) Composite material 0210 nano-technology Electron backscatter diffraction |
Zdroj: | Materials Characterization. 170:110675 |
ISSN: | 1044-5803 |
Popis: | In this work, titanium blocks of Ti-5Al-5Mo-5V-3Cr (Ti-5553) have been Laser Metal Deposited (LMD) on forged substrate of the same alloy under varying laser power and powder feed rates. The microstructure has been characterized using optical microscopy, scanning electron microscopy and Electron backscatter diffraction (EBSD) techniques. Microstructure was predominantly large columnar β-grains aligned with the build direction interspersed with fine equiaxed β-grains. Increase in the powder feed rate was found to reduce the average β-grain size and promoted clusters of fine grains to be retained during the deposition of subsequent layers. Increase in the laser power also reduced the average β grain size and promoted greater nano-scaled α precipitates at the substrate interface and initial deposited layers which significantly increased the microhardness in this area. Dendrites exist due to micro-segregation of solutes during rapid solidification which create preferential regions for α nucleation. A difference in texture was observed between specimens manufactured with varying laser powers: a low laser power produced a cube texture and a higher laser power produced a // BD fibre texture. |
Databáze: | OpenAIRE |
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