Vacuum Hot Pressing Preparation Of Phosphoresce Luminescent Wear-resistant Coating And Its Properties

The novel wear-resistant coating with self-sensing capability developed is successfully prepared by vacuum pressure-assisted sintering. It not only has excellent wear ability and corrosion-resistance of aluminum bronze alloy powder, but also has fine luminous property of phosphorescent materials. The light-emitting properties of the novel coating can serve as an indicator, warning when and where the coating has worn off. It is easy to be applied to online-monitor the wear condition of industrial coatingsLuminescent composite coatings doped with different volume fraction rare earth phosphoresce particles comprised by Cu-14A1-X, Cu and Cu-Al metallic powders respectively were fabricated by vacuum pressure-assisted sintering on45#carbon steel substrate. Microstructure, phase structures of the sintering coatings is investigated by mens of optical microscope, scanning electron microscope, energy dispersion spectroscope and X-ray diffraction analyzer. Hardness and photoluminescence spectroscopy of the coating are measured by hardness tester and optical microscope and fluorescence spectrophotometry. Pin-on-disc friction testing machine (MMW-1A) is used to wear the sintering coatings away. The status of phosphors in the coatings microstructure is studied. Effects of phosphoresce particles volume fraction and metal material elements on the microstructure, phases and luminescent properties is discussed further. In addition, the tribological and wear properties of the coatings on MMW-1A are also analyzed.Various Cu-14A1-X, Cu and Cu-Al metallic powders based composite coatings containing10%,15%,20%,25%,30%,35%,40%,45%,50%and55%(vol) phosphoresce particles, respectively, are prepared by vacuum pressure-assisted sintering. In the macroscopic state, the dispersed phosphoresce particles in the sintering coatings is uniformity. There is the aggregation phenomenon of phosphoresce particles in the microscopic state. With the volume of phosphoresce particles increasing, the aggregation phenomenon in the coatings is more evidently. There also are obverse holes around the phosphoresce particles. After hot pressing, the main phosphorescent crystalline phases in the composite coatings are SrAl2O4and BaAl2O4. To the different metal matrix material of the coatings, microstructure of Cu-14A1-X based composite coatings consist of p+γ2+k phases, the Cu based composite coatings are composed of Cu matrix phases, and the matrix microstructure of the Cu-Al based composite coatings consist of CU3Al+Cu9Al4phases. With the increase of phosphoresce particles volume fraction, surface hardness of the Cu-14A1-X and Cu-Al based composite coatings increase slowly. The hardness of the Cu based composite coatings increases gradually with the raise of phosphoresce particles volume fraction. The BaAl2O4microstructure has the maximum hardness, and the hardness of SrAl2O4microstructure is relatively lower in the coatings.After the sintering process, the equably distributed SrAl2O4phosphor particle emit bright yellow-green excited by UV light, fracture appear inside the agglomerated particles, and the irregular BaAl2O4phosphor emit blue-green light. All these irradiated coatings emit visible yellow-green and blue-green light excited by UV light, which can be identified by naked eye. These broad band emission spectra at510nm are attributed to the4f65d1configuration to4f7(8S7/2) configuration of Eu2+ion transitions. Luminescent intensity increases with phosphoresce particles volume fraction in the sintering coatings. Mechanical deteriorating resulted from the sintering pressure, aggregates in the phosphors and impure phases (SrAl4O47) are generated by the activity of metal material element Al decrease the luminescent intensity of the composite coatings. The Cu, Cu-Al and Cu-14A1-X based composite coatings luminescent intensity showed a decreasing trend. Wear test and luminescent property shows that the Cu-14A1-X based composite coating is indistinguishable under normal lighting, but emit a constant glow under ultraviolet light to monitor wearing conditions.Comparison was made with coatings without phosphoresce particles, the phosphoresce particles can improve the hardness of Cu-14A1-X, Cuand Cu-Al metallic powders based composite coatings, respectively. Differ from the pure Cu-14A1-X sintering coating, the hard phosphoresce particles dispersed in the Cu-14A1-X matix composite coating decrease the wear while it increases the friction coefficient. The wear mechanism of Cu-14A1-X matix composite coating coped phosphoresce particles is mainly slight abrasion wear. The hard phosphoresce particles dispersed in the Cu matix composite coating display more stable and coefficient of friction, and higher wear than the pure Cu sintering coating. The wear surface morphology of both produce the plastic deformation, and the abrasion mechanism is abrasion wear and serious adhesive wear. The more stable friction coefficient of Cu-Al based composite coating increases markedly, and the wear loss is reduced, compared with that of pure Cu-Al sintering coating. The morphology of the wear surface is coarse, and the wear mechanism is a mixture mode of adhesive wear and slight abrasion wear.