Preparation And Properties Of Lanthanum Aluminate Ceramics

The demand for colored ceramics in the field of ornaments is large,but the system of colored ceramics and ceramic colorants is relatively single.The purpose of this article is to prepare lanthanide ceramic pigments and explore the physical and chemical characteristics of such ceramic pigments into porcelain alone,and for ZrO₂ ceramic And the possibility of coloring of Al₂O₃ceramics.Four ceramic pigments,LaAl_11-3xNi_3XO₁₈,LaAl_11.76-2xNi_xTi_xO₁₉,LaAl_11.76-2xNi_xMn_xO₁₉,and LaMgAl_11-xCo_xO₁₉,were prepared by solid-phase high-temperature sintering method at 1350°C.Four kinds of ceramic pigments were sintered into porcelain at a firing temperature of 1450°C to study their various properties,and the ceramic pigments were added to zirconia and alumina to study their application properties.LaAl_11-3xNi_3XO₁₈8 materials prepared using lanthanum oxide,aluminum hydroxide,and nickel oxide by high-temperature solid-phase method were examined and analyzed by X-ray diffraction?XRD?,and it was found that lanthanum hexaaluminate was used as The main crystalline phase contains diffraction peaks of a small amount of intermediate reaction products.The optical properties of the material were measured using a colorimeter and an ultraviolet-visible spectrometer,and the mechanical properties of the prepared sample were measured using a Bouvier hardness tester.Fracture toughness but lower hardness.The micro-morphology of the material was analyzed by field emission scanning electron microscopy,and it was found that the crystal grains were plate-like structures,randomly stacked in the direction of the vertical mirror surface,and the crystal grains were less than 1?m,and were densely sintered.LaAl_11.76-2xNi_xTi_xO₁₉9 material prepared was found to have a phase composition and optical similarity to LaAl_11-3xNi_3XO₁₈8 by X-ray diffractometer,colorimeter,and ultraviolet-visible spectrometer.performance.The micro-morphology of the material was analyzed by field emission scanning electron microscopy,and it was found that the grains were plate-like structures,randomly stacked in the direction of the vertical mirror surface,and the grains were larger than 1?m.LaAl_11.76-2xNi_xMn_xO₁₉9 materials prepared were found to have a phase composition and optical properties similar to LaAl_11-3xNi_3XO₁₈8 by X-ray diffraction.The colorimeter and UV-visible spectrometer have found that the reflectance of the sample is almost zero,the a^*and b^*values representing the color are close to 0,and the sample is grayish black.The micro-morphology of the material was analyzed by field emission scanning electron microscopy,and it was found that the grains were plate-like structures,randomly stacked in the direction of the vertical mirror surface,and the grain size was about 1?m.LaMgAl_11-xCo_xO₁₉9 material prepared from cobalt oxide,aluminum hydroxide,and magnesium oxide was tested and analyzed by X-ray diffraction?XRD?,and the main crystal phase was found to be magnesium-based lanthanum hexaaluminate,Also part of the phase of CoAl₂O₄ and LaAlO₃.The colorimeter and UV-Vis spectrometer were used to test the optical properties of the sample,and it was found that the sample had strong reflection of blue light.The micro-morphology of the material was analyzed by field emission scanning electron microscopy.It was found that the grains were plate-like structures and accompanied by grain boundary fusion.The LaMgAl_11-xCo_xO₁₉?x=1.0?ceramic pigment with the best color effect was selected,and the effect of sintering temperature on the color of the sample was explored.The research found that increasing the sintering temperature can improve the brightness and blue tone of the sample,but after the temperature exceeds 1450?,The effect becomes smaller or even close to zero.Ceramic pigments were fully mixed with zirconia and alumina by mechanical methods,and alumina and zirconia ceramics were prepared by high-temperature solid-phase reaction.The composition of the phases was measured and analyzed by X-ray diffraction?XRD?.It was found that the ceramic pigment phase can coexist with the zirconia and alumina phases,respectively.The optical properties of the prepared colored ceramic samples were measured with a colorimeter and an ultraviolet-visible spectrometer,and there was almost no change compared with the color of the ceramic pigment,which verified the coloring ability of the ceramic pigment.