Showing papers by "Huijun Yu published in 2016"
TL;DR: In this paper, the microstructure, strengthening mechanism, and wear mechanism of the laser cladding coatings were investigated accordingly, and the results showed that the micro-hardness of the composite coatings was 3-4 times the Ti-6Al-4V substrate and the wear resistance was enhanced as high as 18.2 times.
53 citations
TL;DR: In this paper, micro-arc oxidation (MAO) is used to form ceramic bioactive coatings on the ZK61 alloy substrate, and the structure characteristics and element distributions of the coating were investigated by XRD, TEM, SEM and EPMA.
36 citations
TL;DR: In this article, Co42 Co-based self-fluxing alloy, B4C, and CeO2 mixed powders were used as the precursor materials for the fabrication of laser cladding coatings reinforced by multiple phases.
Abstract: In this study, Co-based laser cladding coatings reinforced by multiple phases were fabricated on titanium alloy. Co42 Co-based self-fluxing alloy, B4C, and CeO2 mixed powders were used as the precursor materials. The coatings were mainly composed of γ-Co/Ni, CoTi2, CoTi, NiTi, TiC, Cr7C3, TiB2, and TiB phases. A typical TiB2/Cr7C3/TiC composite structure was chosen. It was found that CeO2 did not influence the phase types of the coating significantly, but was effective in refining the microstructure and enhancing the microhardness and dry sliding wear resistance. Compared with the Ti-6Al-4V titanium alloy, the microhardness and wear resistance of the composite coatings were enhanced by 3.44–4.21 times and 14.26–16.87 times, respectively.
32 citations
TL;DR: In this article, a porous bioceramic containing tricalcium phosphatein (TCP) coating was prepared by micro-arc oxidation (MAO) with different voltages.
22 citations
TL;DR: In this article, micro-arc oxidation (MAO) is applied on ZK61 magnesium alloy at different voltages and the properties of the MAO coating, such as thickness, microstructure, roughness and composition, can easily be controlled by adjusting voltage, current density, duration or the electrolyte concentration.
14 citations
TL;DR: In this paper, the influence of Na2WO4 concentration on the performance of the micro-arc oxidation (MAO) process on 2A12 aluminum alloys using CH3COONa electrolyte was investigated.
Abstract: Ceramic coatings were deposited on 2A12 aluminum alloys using micro-arc oxidation (MAO) technology in CH3COONa-Na2WO4 electrolyte. The MAO process was studied by recording the current-time curve. The influences of Na2WO4 concentrations on the coatings in CH3COONa electrolyte were investigated. The results show that the Na2WO4 concentrations affect the MAO process and performances of the coatings directly. Na2WO4 in excess is harmful for the formation of Al2O3 in this electrolyte. The corrosion resistance was enhanced with the decrease of Na2WO4 concentration.
11 citations
Patent•
21 Dec 2016
TL;DR: In this paper, a calcium-phosphorus-silicon biological ceramic coating and a preparation method and application thereof are described. But the method is not suitable for the use in medical applications.
Abstract: The invention discloses a calcium-phosphorus-silicon biological ceramic coating and a preparation method and application thereof. After magnesium and alloy of magnesium are put in a calcium-phosphorus electrolyte for powered-on electrolysis for a set time, a sample containing a calcium-phosphorus coating is put in a silicon salt electrolyte for powered-on electrolysis, and the target biological ceramic coating is obtained; and the calcium-phosphorus electrolyte is prepared by adding calcium salt and (NaPO3)6 into a basic electrolyte, and the silicon salt electrolyte is prepared by adding silicate into the basic electrolyte. A compact layer is connected with a basal body, the compact layer and the basal body are tightly combined, and the mechanical property of the basal body can be improved; in addition, pores barely exist in the compact layer, body fluid can be prevented from flowing to the surface of the basal body to make contact with the basal body, metal ions generated after the basal body is corroded also can be prevented from being diffused to the human body, toxicity is reduced, and biocompatibility is effectively improved; and a surface layer is a porous loose layer, combination of an implant and a bone can be effectively improved in the presence of micro-pores, growth of adherence bone tissue of bone cells can be effectively improved, and the biological activity of the coating can be improved.
6 citations
TL;DR: In this article, a Ti-Al alloyed coating reinforced by nitrides was fabricated by laser surface alloying technique to improve mechanical properties and high temperature oxidation resistance of Ti-6Al-4V titanium alloy.
Abstract: Ti–Al alloyed coating reinforced by nitrides was fabricated by laser surface alloying technique to improve mechanical properties and high temperature oxidation resistance of Ti–6Al–4V titanium alloy. Microstructures, mechanical properties and high temperature oxidation behavior of the alloyed coating were analyzed. The results show that the alloyed coating consisted of Ti3Al, TiAl2, TiN and Ti2AlN phases. Nitrides with different morphologies were dispersed in the alloyed coating. The maximum microhardness of the alloyed coating was 906HV. The friction coefficients of the alloyed coating at room temperature and high temperature were both one-fourth of the substrate. Mass gain of the alloyed coating oxidized at 800∘C for 1000h in static air was 5.16×10−3mg/mm2, which was 1/35th of the substrate. No obvious spallation was observed for the alloyed coating after oxidation. The alloyed coating exhibited excellent mechanical properties and long-term high temperature oxidation resistance, which improved surface properties of Ti–6Al–4V titanium alloy significantly.
3 citations