39results about How to "Improve hot corrosion resistance" patented technology

The invention provides a multilayer thermal barrier coating and a preparation method thereof. The multilayer thermal barrier coating sequentially comprises an adhesion layer, a first ceramic layer, a second ceramic layer and a closing layer from bottom to top, wherein the closing layer has the thickness of 10-30 micros and the porosity of 2-8 percent and is made from the Al2O3. The thermal barrier coating can be prepared by adopting an electron beam physical gas-phase deposition technology or a plasma spraying method. The multilayer thermal barrier coating provided by the invention can avoid the stripping of the ceramic layers in a thermal circulating process, the thermal erosion resistance of the thermal barrier coating is greatly improved than the dual ceramic layers; and vertical crackles are introduced in the ceramic layer through improving a conventional plasma spraying process so that the thermal shock life of the thermal barrier coating is greatly prolonged.

The invention mainly relates to the coating technique, in particular to a gradient MCrAlY coating used for protecting high-temperature alloy and a preparation method thereof. The invention prepares an MCrAlY composite gradient coating by adopting the method combining the arc ion plating (AIP) and the diffusion aluminizing. The thickness of an aluminum-rich layer on the surface of the MCrAlY composite coating can be controlled by setting the aluminizing temperature and the period of heat preservation and the Al elements are distributed in a gradient way along the depth direction; in addition, the chemical vapor deposition method used for the aluminizing has the advantages of good uniformity on the aluminum-rich layer and being not affected by the size and shape of a sample. Since the method of direct diffusion is adopted without introducing a weak interface, the MCrAlY high-temperature protective coating can increase the content of Al memory phase to the utmost extent under the condition that the mechanical property of the coating is guaranteed, so as to improve the high-temperature oxidization resistance and the heat corrosion resistance of the coating, and can effectively prolong the service life of the coating. The MCrAlY composite gradient coating and the preparation method of the invention can be applied to the protection of Ni-based and Co-based high-temperature alloys.

The invention discloses a process for preparing nickel-base superalloy. The superalloy consists of the following components in percentage by weight: 22.5 to 24.5 percent of Cr, 7.0 to 8.0 percent of Co, 6.5 to 7.5 percent of W, 3.0 to 4.0 percent of Mo, 1.2 to 1.8 percent of Al, 1.5 to 2.5 percent of Ti, 2.0 to 3.0 percent of Nb, 1.0 to 2.0 percent of Mn, 2.0 to 4.0 percent of Fe, 0.02 to 0.08 percent of B, 0.5 to 1.5 percent of Ce, less than or equal to 0.1 percent of C, less than or equal to 0.2 percent of Si, less than or equal to 0.008 percent of P, less than or equal to 0.008 percent of S and the balance of Ni. The process for preparing the nickel-base superalloy comprises a smelting process and a heat treatment process, wherein the smelting process comprises the steps of: smelting master alloy by using a vacuum induction furnace, and performing directional solidification in a liquid metal directional furnace to prepare directional column crystal alloy, wherein the vacuum degree of the directional furnace is about (1-5)*10<-4>mmHg, the pouring temperature is 1,580 to 1,600 DEG C, the drawing speed is 4 to 8mm/min, the temperature gradient is 75 to 85 DEG C/cm, and the temperature of liquid tin is 250 to 350 DEG C; the heat treatment process comprises the following steps of: heating the column crystal alloy obtained through smelting to 1,240 to 1,260 DEG C, preserving heat for 3 to 5 hours, and performing air cooling to room temperature; heating to 1,150 to 1,170, preserving heat for 3 to 5 hours, and performing air cooling to room temperature; and heating to 930 to 950 again, preserving heat for 8 to 12 hours and performing air cooling to room temperature.

The present invention discloses a titanium aluminum alloy surface high temperature oxidation and hot corrosion resistant Al-Cr coating; an Al-rich deposition layer, an Al-Cr alloy layer and a Cr diffusion layer are successively arranged from surface to a titanium aluminum alloy substrate. The content of Al in the Al-rich deposition layer remains the same. The content of Al in the Al-Cr alloy layer gradually reduces outside-to-inside to 70%-100% of the content of Al in the titanium aluminum alloy substrate, and the rest in the Al-Cr alloy layer is Cr. The contents of Cr and Al in the Cr diffusion layer respectively gradually reduces outside-to-inside to same as the contents of Cr and Al in the titanium aluminum alloy substrate, and the rest in the Cr diffusion layer is other elements in the titanium aluminum alloy substrate, and the contents of other elements in the Cr diffusion layer respectively gradually rise to same as the contents of the other elements in the titanium aluminum alloy substrate from zero. The invention also discloses a preparation method of the titanium aluminum alloy surface high temperature oxidation and hot corrosion resistant Al-Cr coating; the titanium aluminum alloy surface high temperature oxidation and hot corrosion resistant Al-Cr coating can give titanium aluminum alloy excellent oxidation resistance and heat resistance corrosion performance under high temperature and long term service conditions, and due to the presence of the diffusion layer of the gradient components, the reliable binding strength and excellent thermal shock resistance can be realized.

The invention discloses a high-entropy high-temperature alloy and a preparation method thereof, and belongs to the field of high-entropy alloys. The alloy comprises the following chemical components of, in percentage by atom, 35%-40% of Ni, 30%-35% of Co, 10%-13% of Al, 5%-10% of Cr, 5%-8.5% of Fe, 1%-2.5% of Ti, 1%-3% of Ta, 0.01%-1% of Mo, 0.01%-1% of W, 0-1% of Re, 0.02%-0.12 % of C, 0.002%-0.015% of B, 0.005%-0.12% of Hf, and 0.05%-0.15% of RE, wherein Al+Ti+Ta is greater than or equal to 14% and less than or equal to 16%, and RE is any one rare earth element of Ce, La and Y. The preparation process of the alloy comprises the following steps of weighing and matching alloy elements according to the molar ratio, putting the alloy elements into a smelting furnace for smelting, carrying out high-temperature refining and casting to obtain an alloy ingot, preparing a (001) oriented single crystal high-entropy high-temperature alloy bar by adopting a high-speed solidification Bridgeman method, and then performing solution treatment and secondary aging treatment on the alloy bar. The prepared alloy bar has good high-temperature strength and thermal corrosion resistance, and is a candidate material of a hot-end part of an aero-engine and an industrial gas turbine.

The invention relates to a NiCrAIY coating for nickel base high temperature alloy. The NiCrAIY coating for the nickel base high temperature alloy is characterized by comprising the following components by weight: 8-25 percent of Cr, 30-40 percent of Al and 0.3-1.5 percent of Y. The NiCrAIY coating and the preparation method thereof can effectively prolong the service life of high temperature alloy components. The inoxidizability of a matrix can be effectively improved under the environment with the temperature below 1100 DEG C; and the hot corrosion resistance of the matrix can be improved under the Cl-containing hot corrosion environment with the temperature below 900 DEG C. The equipment investment and the production cost of the thermal diffusion preparation method are far lower than the existing methods such as thermal spraying, vacuum physical vapor deposition, and the like. Therefore, the NiCrAIY coating and the preparation method thereof have foreseeable tremendous economic value and social value.

The invention discloses a nickel-based high temperature alloy and a manufacturing method thereof. The nickel-based high temperature alloy comprises the following components in percentage by weight: 0.06-0.15% of C, 0.25-0.55% of Si, 0.40-0.95% of Mn, 0.05-3.00% of Fe, 1.0-5.0% of Co, 0.05-0.50% of Al, 0.01-0.09% of Ti, 20.0-24.0% of Cr, 0.01-0.40% of Nb, 0.90-3.0% of Mo, 12.0-15.0% of W, 0.10-1.0% of Re, 0.001-0.009% of B, 0.8-2.0% of Ce, 0.8-1.8% of Ru, 0.3-3.0% of Hf, 2.0-5.0% of Ta, 0.05-0.35% of V and the balance of nickel and inevitable impurities. The nickel-based high temperature alloy disclosed by the invention has the advantages that materials are prepared in a certain proportion, homogenization treatment is carried out on the alloy for three times, high temperature forging is carried out on the alloy, and solution treatment, heat preservation and cooling are carried out; and by adopting the technical scheme of the invention, the strength, fatigue resistance and corrosion resistance of the alloy at high temperature can be effectively improved.

The invention relates to a high-temperature-resistant alloy casting and a preparation method thereof. The alloy casting comprises the following chemical components by mass percent: 0.10% to 0.18% of C, 2.0% to 2.6% of Si, less than or equal to 1% of Mn, less than or equal to 0.045% of P, less than or equal to 0.045% of S, 19% to 23% of Cr, 36% to 40% of Ni, 1.5% to 2.0% of Mo, 0.50% to 0.65% of B, 3.5% to 4.5% of W, 1.0% to 1.4% of Al, 2.0% to 2.6% of Ti, 2% to 3% of Co, 0.05% to 0.15% of Ce and the balance of Fe. The preparation method comprises the following steps of the preparation of a wax mould; the preparation of a mould shell; smelting; and pouring. The as-cast hardness of the alloy casting is HB273-285; and an as-cast metallographic structure of the alloy casting is composed of a fine and small dendritic austenite r, a precipitation strengthening phase r', an intermetallic compound, a metal carbide and a metal boride. The obtained inner core cup casting is strong in high-temperature creep resistance, high-temperature resistance and oxidation resistance and is high in strength and stability under a high-temperature condition, so that the long service life of the casting is realized.

The invention discloses a low-rhenium high-strength thermal-corrosion-resistant nickel-based single-crystal high-temperature alloy and a manufacturing method thereof. The alloy comprises the followingchemical components of, in percentage by weight, 9.0-12.0% of Cr, 8.0-11.0% of Co, 0.2-1.5% of Mo, 4.5-7.0% of W, 3.5-5.5% of Al, 2.0-4.0% of Ti, 4.5%-6.5% of Ta, 0.1-0.3% of Hf, 1.2-2.0% of Re, andthe balance Ni. The high-temperature endurance performance is superior to that of the PWA1483 alloy, the Re element is low, and good thermal corrosion resistance is achieved; compared with the existing nickel-based single-crystal high-temperature alloy, the content of the Cr element in the alloy component is relatively high, the alloy component has relatively high thermal corrosion resistance; thealloy has good high-temperature endurance performance, the high-temperature performance is superior to that of PWA1483, and the creep time of the 982 DEG C/100 Mpa is larger than or equal to 5000h.

The invention discloses a method for improving hot corrosion resistance of Co-Al-W high temperature alloy by utilizing pre-oxidation. The method comprises the following steps: under atmospheric conditions, heating cobalt-based high temperature alloy to 950 DEG C and carrying out oxidation treatment for 50-100 hours to obtain a pre-oxidized layer with the thickness of 2-10 micrometers, wherein thethickness of an Al2O3 layer is 0.5-2 micrometers. The method disclosed by the invention has the advantages that the process is simple and the energy is saved. Compared with un-pre-oxidized alloy, thepre-oxidized alloy has the advantages that the pre-oxidized layer is structurally stable in a corrosive medium and the corrosive medium can be effectively prevented from entering the alloy matrix, sothat the corrosion weight gain of the alloy is significantly reduced by 80% or above and the hot corrosion resistance of the alloy is remarkably enhanced.

The invention discloses a chromium-containing cobalt-based high-temperature alloy and application thereof, and belongs to the field of alloys. The chromium-containing cobalt-based high-temperature alloy consists of the following elements in percentage by atom: (1 to 2) at.% of Cr, (24 to 34) at.% of Ni, (6.5 to 8.5) at.% of Al, (1.5 to 3.5) at.% of Ti and the balance of Co. The sum of the atomic percentage contents of Al and Ti is not more than 10 at.%, and the sum of the atomic percentage contents of Cr, Co, Ni, Al and Ti is 100 at.%. The cobalt-based high-temperature alloy containing the chromium element has high high-temperature corrosion resistance and tensile property, and is applied to high-temperature part materials for aerospace engine manufacturing, industrial gas engine wheel manufacturing and heat exchanger manufacturing.

The invention discloses nickel-base superalloy. The nickel-base superalloy is composed of, by weight, 25.5%-28.5% of Cr, 4.0%-6.0% of Co, 2.5%-5.5% of W, 1.0%-3.0% of Mo, 0.2%-1.0% of Al, 2.6%-4.2% of Ti, 3.5%-6.3% of Nb, 1.0%-2.0% of Mn, 2.0%-4.0% of Ta, 0.02%-0.08% of B, 0.5%-1.5% of Co, 1.4%-3.8% of Ru, 0.1%-1.2% of Hf, 0.01%-0.8% of Re, 0.1% of C or less, 0.15% of Si or less, 0.005% of P or less, 0.005% of S or less and the balance Ni.

The invention discloses a processing method capable of improving the hot corrosion resistance of a diamond grinding material. The processing method comprises the following steps: S1, after washing a diamond, drying; then immersing the diamond into TiO2 sol; after standing, taking out the diamond; then drying to obtain a material A; S2, putting the material A into phenolic aldehyde sol; after standing, taking out the material A and drying to obtain a material B; S3, putting the material B into silicon dioxide sol; after standing, taking out the material B; then drying, raising the temperature and carrying out heat insulation; then cooling and carrying out heat insulation; then cooling to room temperature. According to the processing method capable of improving the hot corrosion resistance of the diamond grinding material, provided by the invention, the prepared diamond grinding material has good hot corrosion resistance and toughness and the service life of the diamond grinding materialcan be prolonged.

The invention belongs to the technical field of bonding layer materials, and particularly relates to a eutectic alloy and a preparation method and application thereof. The eutectic alloy provided by the invention comprises an AlCoCrNiPt alloy and an active element which is dispersed in the AlCoCrNiPt alloy, the AlCoCrNiPt alloy is prepared from the following elements in percentage by atomic number: 18 to 23 at. Percent of Al, 18 to 23 at. Percent of Co, 18 to 23 at. Percent of Cr, 15 to 20 at. Percent of Pt and the balance of Ni. The active element accounts for 0.01 to 0.5 at.% of the atomic number of the eutectic alloy; the eutectic alloy comprises a beta (B2) phase and a gamma '(L12) phase. The eutectic alloy contains high-content Pt which occupies nickel sites in NiAl and Ni3Al, so that the Al/Ni ratio of each crystal face of the alloy is increased, selective oxidation of aluminum oxide is promoted, generation of transient oxides such as nickel oxide is inhibited, and the oxidation resistance of the eutectic alloy is improved. The high-content chromium in the eutectic alloy improves the thermal corrosion resistance of the alloy. The beta (B2) and gamma '(L12) double-phase structure provides a large number of channels for rapid diffusion of Al, rapid formation of a single Al2O3 oxidation film is promoted, and therefore the oxidation resistance of the eutectic alloy is improved.