Influence of Ni Contents on Microstructure and Mechanical Performance of AlSi10Mg Alloy by Selective Laser Melting

Abstract

To improve the tensile strength and wear resistance of AlSi10Mg alloys, a novel in situ synthesis method of selective laser melting (SLM) was used to fabricate the Ni-reinforced AlSi10Mg samples. The eutectic Si networks formed around the α-Al crystals by diffusion and transportation via Marangoni convection in the SLM process. Moreover, the XRD and TEM results verified that the Al3Ni nanoparticles were created by the in situ reaction of the Ni and aluminum matrix in the Ni/AlSi10Mg samples. Therefore, the microstructure of the Ni-containing alloys was constituted by the α-Al + Si network + Al3Ni phases. The dislocations accumulated at the continuous Si network boundaries and cannot transmit across the dislocation walls inside the Si network. SEM results revealed that the continuity and size of eutectic Si networks can be tailored by adjusting the Ni contents. Furthermore, the Al matrix also benefited from the Al3Ni nanoparticles against the dislocation movement due to their excellent interfacial bonding. The 3Ni-AlSi10Mg sample exhibited high mechanical properties due to the continuous Si networks and Al3Ni nanoparticles. The tensile strength, elongation, Vickers hardness, friction coefficient, and wear volumes of the 3Ni-AlSi10Mg samples were 401.15 ± 7.97 MPa, 6.23 ± 0.252%, 144.06 ± 0.81 HV, 0.608, 0.11 mm3, respectively, which outperformed the pure AlSi10Mg samples (372.05 ± 1.64 MPa, 5.84 ± 0.269%, 123.22 ± 1.18 HV, 0.66, and 0.135 mm3).

Improving the Properties of Gray Cast Iron by Laser Surface Modification

“…1 and 7 have smaller COFs (0.3 or 0.4) than other laser-quenched specimens in the same group but larger COFs than the untreated cast iron specimen. This finding contradicts previous studies that laser surface treatment can reduce the COFs of laser-modified surfaces [ 14 ]. A possible reason is that in this study, a higher laser power, more than 2000 W, was used.…”

“…Many traditional surface treatment techniques have been used to improve the mechanical, physical, and chemical properties of the surfaces of metal parts, such as surface coating, diamond-like carbon (DLC) [ 4 , 5 ], abrasive jet machining (AJM) [ 6 , 7 ], micro-electrical etching (MEE) [ 8 ], etc. However, based on the fast-growing laser technology, laser surface treatment is becoming more popular in functional surface modification due to its advantages that have been widely studied in recent decades [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Laser quenching has been shown to be an effective approach to improve the wear resistance, residual stress, local hardness, and structural mechanical properties of functional materials.…”

Solidification Mechanism of Microstructure of Al-Si-Cu-Ni Alloy Manufactured by Laser Powder Bed Fusion and Mechanical Properties Effect

“…As depicted in Figure 1, beyond the diffraction peaks of Al and Si, there are also minor peaks corresponding to binary phases of Al-Cu and Al-Ni, as well as ternary phases of Al-Cu-Ni. This observation is consistent with reported phases in the literature [18][19][20]. Notably, no peaks corresponding to elemental Cu or Ni are detected, indicating that sufficient alloying of Cu and Ni elements has occurred after PBF-LB/M processing.…”

The Influence of the Proportions of Titanium and Boron in the Al and AlSi7-Based Master Alloy on the Microstructure and Mechanical Properties of Hypoeutectic Silumin, AlSi7Mg

“…The process of the chemical modification of hypoeutectic silumins was described in 1921 [41]. Since then, a lot of works have been written showing the influence of various elements, chemical compounds [42][43][44][45] and the technological processes [46][47][48][49][50][51][52][53][54][55][56][57] on the microstructure and mechanical properties of the tested silumins. Unfortunately, despite such a significant amount of research, it has not been possible to clearly identify the mechanisms causing microstructure refinement and increases in mechanical properties.…”