44results about How to "Good phase stability at high temperature" patented technology

The invention provides a shining thermal barrier coating system of rare earth niobate based on a defective fluorite structure and a preparation method of the shining thermal barrier coating system. The preparation method comprises the following steps that Ln2O3 powder and Nb2O3 powder are calcined for one hour at the temperature of 1000 DEG C and mixed at the stoichiometric ratio, absolute ethyl alcohol serves as mixing graft, zirconia is used as a ball-milling medium ball-milling mixed material, and after rotary evaporation and drying, presintered powder is obtained; dry pressing and forming are conducted to obtain a blank; the blank is subjected to pressureless sintering in air and then uniformly mixed with Ln3NbO3, and high-fluidity powder is formed through spray granulation and dry treatment; and a layer of metal bonding layer McrAlY alloy is deposited on the surface of a cobalt-based or nickel-based metal substrate, the high-fluidity powder is deposited on the surface of a metal bonding layer to form a ceramic layer through an ion spray technology, an electron beam physical vapor deposition technology or other spray technologies, and the thermal barrier coating system is formed. The shining thermal barrier coating system of the rare earth niobate is integrated in structure and function, and low in heat conductivity.

The invention discloses a high-fracture-toughness thermal barrier coating material of high-entropy rare earth aluminate toughened high-entropy rare earth zirconate and a preparation method of the high-fracture-toughness thermal barrier coating material. The thermal barrier coating material is x [nRE1 / nAlO3]-(1-x) [n (RE1 / n) 2Zr2O7] (x is more than 0 and less than or equal to 0.5, and n is more than or equal to 5 and less than or equal to 13). The preparation method comprises the following steps: S1, preparing a rare earth source, a zirconium source and an aluminum source according with a stoichiometric ratio into a mixed solution; s2, the mixed solution is added into an ammonia water solution in a stirring state, and the pH value of the system is always kept to be larger than or equal to 10.0; s3, washing and drying a precipitation product obtained in S2; and S4, heat treatment is conducted, and heat treatment is conducted for 2-20 h at the temperature of 950-1600 DEG C. The double-phase high-entropy thermal barrier coating material has good high-temperature phase stability and high fracture toughness, and the fracture toughness of the double-phase high-entropy thermal barrier coating material reaches 1.92 MPa.m < 1 / 2 > to 2.77 MPa.m < 1 / 2 >.

The invention discloses a pyrochlore structural rare-earth zirconate material system capable of being used for a heat barrier coating. The chemical composition of the material is (0.5-x)R'2O3-0.5Sm2O3-xR''2O3-2ZrO2, wherein x is more than 0 and less than or equal to 0.25; the R' is rare-earth elements or composition thereof, the ion radius of which is greater than that of Sm; and R'' is rare-earth elements or composition thereof, the ion radius of which is smaller than that of Sm. The material provided by the invention has low thermal conductivity, high thermal stability and high-temperature sintering resistance; the thermal expansion performance of the material is stable compared with a single pyrochlore structural material; and the material is favorable for reducing thermal stress generated by mismatching of thermal expansion coefficients in the thermal cycle process, and can prolong the thermal cycle life of the coating. Because of good high-temperature phase stability, the pyrochlore structural rare-earth zirconate material can be used for designing and preparing a novel high-temperature heat barrier coating material, the use temperature of which is below 1,550 DEG C.

The invention belongs to material technology, a high-temperature thermal barrier coating material and a preparation method thereof. When used at a high temperature, the conventional thermal barrier coating material is easy to undergo phase change and cause the failure of a coating. The general formula of a multi-component rare-earth high-temperature thermal barrier coating material is that: LnyLn<'>zLn<''>1-y-zMexAl12-xO19+delta, wherein Ln, Ln<'> and Ln<''> are rare earth elements such as La, Ce, Nd, Sm, Gd, Dy, Er and Yb; Me is metal elements such as Mn, Mg, Ni, Co, Sr, Ca and Ba; x is between 0 and 12; y is between 0 and 1; z is between 0 and 1; and y+z is less than or equal to 1. The preparation method comprises the following steps of: preparing mixed metal salt solution; preparing complexing agent solution; preparing mixed metal ion sol; and drying the mixture at the temperature of between 70 and 180 DEG C, and grinding and calcining the dried product to obtain the high-temperature thermal barrier coating material. The high-temperature thermal barrier coating material has the advantages of high temperature resistance, melting point of over 2,000 DEG C, high stability of high-temperature phase, no phase change from room temperature to 2,000 DEG C or higher temperature and low thermal conductivity.

The invention discloses a Sm-Gd-Dy tri-rare-earth ion tantalate and a preparation method and application thereof. The general chemical formula of the Sm-Gd-Dy tri-rare-earth ion tantalate is SmGdDy<c>TaO<7>, wherein the a, b and c meet the relationship of a+b+c=3 and are separately in a range of 0.8-1.2. The preparation method comprises the following steps: (1) weighing samarium nitrate, gadolinium nitrate, dysprosium nitrate and tantalum oxalate according to a stoichiometric ratio, performing mechanical mixing with citric acid with a preset amount under a heat preservation condition, adding a concentrated ammonia water neutralization solution during the mixing process, and carrying out mechanical mixing to promote a complexation reaction under a heat preservation condition; and (2)drying the obtained solution, and then carrying out calcination at a high temperature to remove carbon impurities to obtain the Sm-Gd-Dy tri-rare-earth ion tantalate powder. The Sm-Gd-Dy tri-rare-earth ion tantalate has good high-temperature thermal stability and low thermal conductivity, and can be used as a thermal barrier coating material.

The invention discloses a SiC-doped Gd2Zr2O7 thermal barrier coating ceramic layer material and a preparation method thereof. The chemical formula of the SiC-doped Gd2Zr2O7 thermal barrier coating ceramic layer material is Gd2Zr2O7-XTiSi2-YC (X=0-5wt%, Y =0-1.7wt%), Gd2Zr2O7-XTiSi2-YC (X=0-5wt%, Y=0-1.7wt%) series thermal barrier coating ceramic layer materials, have the following significant advantages: doping different contents of in-situ After the second phase substance SiC is formed, it can still maintain good high temperature phase stability and good sintering resistance at 1500°C. The thermal expansion coefficient can reach 11W / m.K, the thermal conductivity at 1000°C can reach 0.6‑0.7W m‑1 k‑1, and the fracture toughness can be increased to 1.5‑1.6MPa m1 / 2. Barrier coating ceramic layer material.