scholarly journals High Bending Strength Hypereutectic Al-22Si-0.2Fe-0.1Cu-Re Alloy Fabricated by Selective Laser Melting

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 528
Author(s):  
Chunyue Yin ◽  
Zhehao Lu ◽  
Xianshun Wei ◽  
Biao Yan ◽  
Pengfei Yan

The objective of the study is to investigate the corresponding microstructure and mechanical properties, especially bending strength, of the hypereutectic Al-Si alloy processed by selective laser melting (SLM). Almost dense Al-22Si-0.2Fe-0.1Cu-Re alloy is fabricated from a novel type of powder materials with optimized processing parameters. Phase analysis of such Al-22Si-0.2Fe-0.1Cu-Re alloy shows that the solubility of Si in Al matrix increases significantly. The fine microstructure can be observed, divided into three zones: fine zones, coarse zones, and heat-affected zones (HAZs). Fine zones are directly generated from the liquid phase with the characteristic of petaloid structures and bulk Al-Si eutectic. Due to the fine microstructure induced by the rapid cooling rate of SLM, the primary silicon presents a minimum average size of ~0.5 μm in fine zones, significantly smaller than that in the conventional produced hypereutectic samples. Moreover, the maximum value of Vickers hardness reaches ~170 HV0.2, and bending strength increases to 687.70 MPa for the as-built Al-22Si-0.2Fe-0.1Cu-Re alloys parts, which is much higher than that of cast counterparts. The formation mechanism of this fine microstructure and the enhancement reasons of bending strength are also discussed.

2021 ◽  
Vol 1027 ◽  
pp. 130-135
Author(s):  
Shuai Li ◽  
Bi Zhang ◽  
Cong Zhou

Selective laser melting (SLM) is a promising technique to build grinding wheels with complex structures. In this paper, Ni-based self-fluxing alloys are chosen as bond materials to investigate single track formation on a steel substrate under different processing parameters. Results show that irregular and balling tracks are obtained with a low linear energy density (LED). The width of a melt pool increases linearly with LED. For LED values larger than around 0.9 J/mm, keyhole occurs in the melt pool, which is not desirable in the SLM process. Energy dispersive spectroscopy (EDS) mapping is performed to investigate the formation of the melt pool. Through an analysis on chemical distributions, it is found that the melt pool has a mixture of the partly melted substrate and powders. However, in the keyhole region, only the alloying elements of the substrate are detected due to the repulsion of the melted powder materials caused by the recoil pressure. This work can offer guidance on parameter optimization for the fabrication of SLMed grinding wheels.


2010 ◽  
Vol 97-101 ◽  
pp. 4020-4023
Author(s):  
Jin Hui Liu ◽  
Rui Di Li ◽  
Can Zhao

Melting tracks with and without powder materials were studied by varying the parameters in selective laser melting. Several characters of melting track such as melting width and gilled state stripes were analyzed combining the relationship between the powder materials and processing parameters. Connected with balling effects, thermal transmission and thermal physical properties of powder materials, the formation of above character were explained. The research result of this work would provide a basic foundation for the further investigation of the quality of end metal component manufactured by selective laser melting method.


2016 ◽  
Vol 51 (4) ◽  
pp. 519-532 ◽  
Author(s):  
Jiubin Jue ◽  
Dongdong Gu

The advanced selective laser melting technology was employed to prepare in situ Al based composites. Relationship among selective laser melting processing parameters, microstructures and resultant mechanical properties had been established. It turned out that in situ Al2Si4O10/Al composites were successfully fabricated by selective laser melting of Al2O3/AlSi10Mg composite powders. Due to the overlap between neighboring tracks and the remelting of previously solidified layers, two distinguished zones consisting of track core and track overlap were produced in laser induced melt pool. The two zones, respectively experienced different thermal histories, thus leading to the variation of cooling rate, which had a significant influence on the microstructural development and resultant mechanical performances. The track core mainly consisted of remarkably refined cellular dendritic Al matrix decorated with uniformly distributed ring-structured Al2Si4O10 reinforcements, while the track overlap was characterized with comparatively coarse columnar dendritic Al matrix as well as the coarse Al2Si4O10 reinforcements. At the optimal v of 500 mm/s, the obtained dynamic nanohardness ( H d) of track core ( H d = 3.79 GPa) and track overlap ( H d = 3.52 GPa) for selective laser melting processed composites part both showed tremendous enhancement upon that of unreinforced Al part ( H d = 0.58 GPa). The dry sliding wear tests indicated that the optimally prepared Al2Si4O10/Al composites part exhibited excellent wear performance with a considerably low coefficient of friction of 0.32 and a significantly reduced wear rate of 4.52 × 10−5 mm3 N−1 m−1. The formed consecutive protective adherent tribolayer on the worn surface and the significantly enhanced hardness of the composites well accounted for the superior wear performance.


2018 ◽  
Vol 8 (10) ◽  
pp. 1879 ◽  
Author(s):  
Luis Santos ◽  
Joel de Jesus ◽  
José Ferreira ◽  
José Costa ◽  
Carlos Capela

Selective Laser Melting (SLM) is currently one of the more advanced manufacturing and prototyping processes, allowing the 3D-printing of complex parts through the layer-by-layer deposition of powder materials melted by laser. This work concerns the study of the fracture toughness of maraging AISI 18Ni300 steel implants by SLM built over two different conventional steels, AISI H13 and AISI 420, ranging the scan rate between 200 mm/s and 400 mm/s. The SLM process creates an interface zone between the conventional steel and the laser melted implant in the final form of compact tension (CT) samples, where the hardness is higher than the 3D-printed material but lower than the conventional steel. Both fully 3D-printed series and 3D-printed implants series produced at 200 mm/s of scan rate showed higher fracture toughness than the other series built at 400 mm/s of scan rate due to a lower level of internal defects. An inexpressive variation of fracture toughness was observed between the implanted series with the same parameters. The crack growth path for all samples occurred in the limit of interface/3D-printed material zone and occurred between laser melted layers.


2010 ◽  
Vol 53 (4) ◽  
pp. 310-317 ◽  
Author(s):  
R. D. Li ◽  
J. H. Liu ◽  
Y. S. Shi ◽  
L. Zhang ◽  
M. Z. Du

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.


2016 ◽  
Vol 2016 (1) ◽  
pp. 000517-000522
Author(s):  
Aarief Syed-Khaja ◽  
Christopher Kaestle ◽  
Joerg Franke

Abstract Additive manufacturing (AM) has the potential to lead significant changes in the present state-of-the-art production processes. This provides tool-free and direct manufacturing of complex geometries simultaneously integrating various functions into components. Though AM techniques are widely used in various sectors, the application into electronics production has been not yet explored. In electronics production, substrate development has high relevance due to their multi-functionality in giving the mechanical support and electrically connecting electronic components. This contribution introduces an innovative approach in the development of high-temperature substrates through additive layered manufacturing. The technique used in the investigations was selective laser melting (SLM) of copper based powder materials mainly bronze alloy and pure copper, for the generation of conductive patterns on ceramic surfaces. The process parameters for the SLM technique and the influential factors in the generation of conductive structures are discussed in detail.


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