Microstructure and mechanical properties of multilayer (TiB+TiB2+TiC)/Ti-6Al-4V composite in laser powder bed fusion additive manufacturing process

Abstract The paper presents the analysis of the physical and mechanical properties of the heterogeneous material based on the ceramics TiB, TiB2, TiC, B4C and metal alloy Ti-6Al-4V formed by the SLM method. The effect of ceramic particles TiB, TiB2, TiC, B4C resulting from in situ synthesis under the laser action on the microstructure and hardness of the formed metal-matrix composite has been studied. Under discussion are the main mechanisms of change of the microstructure with secondary ceramic insertions, the hardness is measured at the micro-level.

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Effect of Particle Size Distribution on Laser Powder Bed Fusion Manufacturability of Copper

BHM Berg- und Hüttenmännische Monatshefte ◽

10.1007/s00501-021-01107-0 ◽

2021 ◽

Author(s):

Massimiliano Bonesso ◽

Pietro Rebesan ◽

Claudio Gennari ◽

Simone Mancin ◽

Razvan Dima ◽

...

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Physical And Mechanical Properties ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Cooling Channels ◽

Scan Speed

AbstractOne of the major benefits of the Laser Powder Bed Fusion (LPBF) technology is the possibility of fabrication of complex geometries and features in only one-step of production. In the case of heat exchangers in particular, this is very convenient for the fabrication of conformal cooling channels which can improve the performance of the heat transfer capability. Yet, obtaining dense copper parts printed via LPBF presents two major problems: the high reflectivity of 1 μm (the wavelength of commonly used laser sources) and the high thermal conductivity of copper that limits the maximum local temperature that can be attained. This leads to the formation of porous parts.In this contribution, the influence of the particle size distribution of the powder on the physical and mechanical properties of parts produced via LPBF is studied. Three copper powders lots with different particle size distributions are used in this study. The effect on densification from two laser scan parameters (scan speed and hatching distance) and the influence of contours scans on the lateral surface roughness is reported. Subsequently, samples manufactured with the optimal process parameters are tested for thermal and mechanical properties evaluation.

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In Situ Formation of a Metastable β-Ti Alloy by Laser Powder Bed Fusion (L-PBF) of Vanadium and Iron Modified Ti-6Al-4V

Metals ◽

10.3390/met8121067 ◽

2018 ◽

Vol 8 (12) ◽

pp. 1067 ◽

Cited By ~ 2

Author(s):

Florian Huber ◽

Thomas Papke ◽

Christian Scheitler ◽

Lukas Hanrieder ◽

Marion Merklein ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Homogeneous Element ◽

Alloy Formation ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Β Phase ◽

Stabilizing Effect

The aim of this work is to investigate the β-Ti-phase-stabilizing effect of vanadium and iron added to Ti-6Al-4V powder by means of heterogeneous powder mixtures and in situ alloy-formation during laser powder bed fusion (L-PBF). The resulting microstructure was analyzed by metallographic methods, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The mechanical properties were characterized by compression tests, both prior to and after heat-treating. Energy dispersive X-ray spectroscopy showed a homogeneous element distribution, proving the feasibility of in situ alloying by LPBF. Due to the β-phase-stabilizing effect of V and Fe added to Ti-6Al-4V, instead of an α’-martensitic microstructure, an α/β-microstructure containing at least 63.8% β-phase develops. Depending on the post L-PBF heat-treatment, either an increased upsetting at failure (33.9%) compared to unmodified Ti-6Al-4V (28.8%), or an exceptional high compressive yield strength (1857 ± 35 MPa compared to 1100 MPa) were measured. The hardness of the in situ alloyed material ranges from 336 ± 7 HV0.5, in as-built condition, to 543 ± 13 HV0.5 after precipitation-hardening. Hence, the range of achievable mechanical properties in dependence of the post-L-PBF heat-treatment can be significantly expanded in comparison to unmodified Ti-6Al-4V, thus providing increased flexibility for additive manufacturing of titanium parts.

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In situ synthesis, physical and mechanical properties of ZrB2–ZrC–WB composites

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2019.04.040 ◽

2019 ◽

Vol 39 (11) ◽

pp. 3283-3291

Author(s):

Shuqi Guo

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

In Situ Synthesis

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In Situ Alloying of a Modified Inconel 625 via Laser Powder Bed Fusion: Microstructure and Mechanical Properties

Metals ◽

10.3390/met11060988 ◽

2021 ◽

Vol 11 (6) ◽

pp. 988

Author(s):

Giulio Marchese ◽

Margherita Beretta ◽

Alberta Aversa ◽

Sara Biamino

Keyword(s):

Mechanical Properties ◽

Base Alloy ◽

Heat Treatments ◽

Inconel 625 ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Melt Pool ◽

Composition Modification

This study investigates the in situ alloying of a Ni-based superalloy processed by means of laser powder bed fusion (LPBF). For this purpose, Inconel 625 powder is mixed with 1 wt.% of Ti6Al4V powder. The modified alloy is characterized by densification levels similar to the base alloy, with relative density superior to 99.8%. The material exhibits Ti-rich segregations along the melt pool contours. Moreover, Ti tends to be entrapped in the interdendritic areas during solidification in the as-built state. After heat treatments, the modified Inconel 625 version presents greater hardness and tensile strengths than the base alloy in the same heat-treated conditions. For the solution annealed state, this is mainly attributed to the elimination of the segregations into the interdendritic structures, thus triggering solute strengthening. Finally, for the aged state, the further increment of mechanical properties can be attributed to a more intense formation of phases than the base alloy, due to elevated precipitation strengthening ability under heat treatments. It is interesting to note how slight chemical composition modification can directly develop new alloys by the LPBF process.

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