The Influence of Neodymium Element on the Crater Structure Formed on Al-17.5Si Alloy Surface Processed by High-Current Pulsed Electron Beam

Abstract

The effect of neodymium element on the elimination of crater structures on the surface of Al-17.5Si metallic materials processed by high-current pulsed electron beam was investigated in this study. Field emission scanning electron microscopy analysis indicated that the grain sizes of Al-17.5Si metallic materials were reduced and craters were removed from surfaces of the processed Al-17.5Si metallic material after addition of Nd. This can be attributed to the efficient transfer of heat accumulated in rich-silicon (primary silicon) areas without the eruption of a primary silicon phase if the size of primary silicon grains are small. The X-ray diffraction analysis indicates that all diffraction peaks are broadened because of the presence of structural defects, grain refinement and stress state. Electron probe micro-analyzer analysis demonstrated that Al and Nd were evenly distributed on the surface of the treated alloy, which could be attributed to the diffusion of the element. Transmission electron microscopy analysis showed that nano-Al and nano-Si cellular textures were generated during the treated process. The formation of these structures can be attributed to rapid heating and cooling effects by the treatment. Finally, electrochemical tests revealed that the corrosion current density of Al-17.5Si metallic materials (with Nd, 0.3 wt.%.) surface decreased by three orders of magnitude compared with that of the processed Al-17.5Si metallic material surfaces (without Nd). This can be attributed to the elimination of craters and grain refining.

Effect of Cerium and Magnesium on Surface Microcracks of Al–20Si Alloys Induced by High-Current Pulsed Electron Beam

“…In addition, a compact and stable passivation film of alumina is formed in the modified surface layer because of the presence of metastable structures (e.g., nanocrystalline structure), thus improving the anticorrosion property of the alloy surface. Therefore, the combined effects of the grain refinement and the microcrack elimination contribute to the improved anticorrosion property of the alloy surface [1,42].…”

Spheroidization Behavior of Nano-Primary Silicon Induced by Neodymium under High-Current Pulsed Electron Beam Irradiation

“…The addition of Nd removes the craters that degrade friction performance [19]. Rare earths can purify a material, reduce the number of casting defects and lower the surface roughness of the material.…”

Effect of High-Current Pulsed Electron Beam on Properties of Graphene-Modified Aluminum Titanium Carbide Composites

“…As a high-density energy source, HCPBE can achieve energy deposition on the material surface in a short time, irradiating the metal surface for rapid heating and cooling [11][12][13][14][15]. According to the literature, HCPEB treatment can refine the surface microstructure of metal, induce the melting of the aluminum matrix on the surface, fill the pores of the material and greatly improve the wear resistance, hardness and other properties [16][17][18][19][20][21]. However, few research works have reported on the effects of electron beams on the electrical conductivity of a treated sample.…”