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 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.