Disclosed are an alumina-based ceramic core removal method and a special device thereof. The method includes placing a hollow blade with an alumina-based ceramic core into a reaction kettle fully filled with lye, and then sealing the reaction kettle; heating the reaction kettle in high-temperature, high-pressure and airtight environment; decreasing the pressure of the reaction kettle till being lower than the saturated vapor pressure of the lye, allowing the lye to be boiled to enter channels of the hollow blade for 10 to 30 seconds; recovering the pressure in the reaction kettle to stop boiling the lye and recover stable statues; removing residual lye and removed ceramic core from the hollow blade, and finally utilizing acid to neutralize residual lye on the hollow blade, and washing with water. The method has the advantages that reacted waste lye in the cavity of the hollow blade can be discharged rapidly through high temperature and increasing and decreasing the pressure repeatedly, good stirring effect is provided by periodically boiling the lye, the lye is guaranteed contacting with the alumina-based ceramic core fully, reacting efficiency is improved, and removal speed of the alumina-based ceramic core is increased significantly.

Alumina-based ceramic core removal method and special device thereof

A method for removing a ceramic core of a hollow blade of a turbine of an aircraft engine comprises the four steps of primary core removing, secondary core removing, third core removing and ultrasonic cleaning. The concentration of KOH alkali liquor used in primary core removing is 40%, the concentration of KOH alkali liquor used in secondary core removing is 30%, and the concentration of KOH alkali liquor used in third core removing is 40%. Every time core removing is conducted, the temperature of the alkali liquor ranges from 160 DEG C to 200 DEG C, the pressure of the alkali liquor fluctuates between 0.4 MPa and 0.5 MPa, water is added every six hours, and soaking time is 48 hours. According to the method, the concentration of the alkali liquor is reduced, the water is added every six hours, and it is guaranteed that salt generated due to reactions is sufficiently dissolved; the alkali liquor is replaced every 48 hours, the concentration of the alkali liquor changes in a stepped mode, and it can be guaranteed that the chemical reactions are conducted effectively; the pressure of the alkali liquor fluctuates in a pulse mode, core cracking can be facilitated, the reaction interface between the alkali liquor and the core is enlarged, and the reacting dose is increased. Through the method, the ceramic core removing period can be shortened to six days from over twenty days, and the first pass yield of core removing can be higher than 90%.

Method for removing ceramic core of hollow blade of turbine of aircraft engine

The invention discloses a hollow blade ceramic mold and a core removal method thereof. The ceramic mold comprises a mold shell and a blade prototype fixed into the mold shell. Ceramic slurry is poured into an inner cavity of the mold shell. A plurality of core bars are distributed into the ceramic slurry. A prepositioning device for fixing the core bars is arranged on the mold shell. Each core bar is composed of a corrosion resistance core portion and a corrosive cladding layer wrapping the corrosion resistance core portion. The core removal method of the ceramic mold sequentially comprises the steps that the core bars are prepared, the core bars are installed inside the mold shell in a positioned mode, the ceramic slurry is poured into the inner cavity of the mold shell with the blade prototype, and the core bars are wrapped by the ceramic slurry; the outer-layer mold shell is taken out after molding, and the blade with a ceramic mold core is manufactured; finally, the blade containing the ceramic mold core is removed; when the corrosive cladding layers on the surfaces of the core bars are corroded completely, the corrosion resistance core portions are taken out, and core removal continues to be performed on the blade till the ceramic mold core is removed completely. The core bars can enhance the strength of the mold core, and the reaction rate is increased during core removal.

Hollow blade ceramic mold and core removal method thereof

The invention discloses a preparation method of a solid cored welding wire for molten-salt corrosion resistance nickel-base superalloy welding, and belongs to the technical field of metal welding. The method includes the technological processes of vacuum smelting, vacuum arc remelting, homogenization, hot forging cogging, hot rolling, solution treatment, acid pickling, coating, cold drawing, coating removal and bright annealing. The invention further discloses the solid cored welding wire for molten-salt corrosion resistance nickel-base superalloy welding. The solid cored welding wire is prepared through the method. Compared with the prior art, by the adoption of the method, high-quality solid cored welding wires of various diameters for molten-salt corrosion resistance nickel-base superalloy welding can be produced with the extremely-high rolling yield in a batch mode, and the prepared solid cored welding wire can meet the requirement for welding molten-salt reactor structural materials.

Preparation method of solid cored welding wire for molten-salt corrosion resistance nickel-base superalloy welding

The invention discloses a welding flux formolten salt corrosion resistant nickel-base superalloy fusion welding and belongs to the technical field of welding materials. The welding flux comprises the following components in percentage by weight: 0.03%-0.06% of C, 0.04%-0.10% of Mn, 0.3%-0.5% of Si, not greater than 0.10% of Cu, not greater than 0.20% of Co, not greater than 0.015% of P, not greater than 0.015% of S, 0.01%-0.05% of rare earth element, 1.0%-5.0% of Fe, 6.0%-8.0% of Cr, 12.0%-18.0% of Mo, not greater than 0.3% of Al, not greater than 0.2% of Ti, 1.0%-2.0% of Nb and the balance of Ni, wherein Ti+Nb+Al is not greater than 2%. The invention also discloses a welding material for molten salt corrosion resistant nickel-base superalloy fusion welding, a connecting method of a molten salt corrosion resistant nickel-base superalloy and a structural member of the molten salt corrosion resistant nickel-base superalloy. According to the welding flux for molten salt corrosion resistant nickel-base superalloy fusion welding, the toughness and the oxidation resistance of a welded joint can be effectively improved, the excellent molten salt corrosion resistance and the excellent high temperature mechanical property can be guaranteed, the usage demands of molten salt and radiation environments with high usage temperature and performance requirements can be satisfied, and the welding flux is suitable for welding of a molten salt reactor structural material.

Welding flux for molten salt corrosion resistant nickel-base superalloy fusion welding

Composite efficient ceramic core demolding process and special equipment thereof

Belonging to the technical field of metal materials, the invention discloses a molten salt corrosion resistant nickel-based superalloy with excellent performance. In terms of weight percentage, the alloy comprises: less than or equal to 0.08% of C (preferably in the range of 0.03-0.06%), 0.5-5% of Fe, 6.0-8.0% of Cr, 12-18% of Mo, less than or equal to 2% of Ta, less than or equal to 2% of Ti, less than or equal to 2% of Nb, and the balance Ni, wherein the sum of Ti, Nb and Ta is greater than or equal to 1% and less than or equal to 2%. In addition to excellent room temperature plasticity, high temperature structure stability and high mechanical properties under high temperature, the alloy also has good resistance to molten salt corrosion, and can meet the use demands of molten salts and irradiation environments with high use temperature and performance requirements. Thus, the molten salt corrosion resistant nickel-based superalloy is suitable for high-temperature structural materials of molten salt nuclear reactors.

Molten salt corrosion resistant nickel-based superalloy with excellent performance

The invention discloses a macrograin corrosion method for a monocrystal high-temperature alloy casting containing Re and/or Ru, belonging to the technical field of quality detection of a turbine blade serving as a core hot end part of an aircraft and airspace engine and a gas turbine for civilian use. A corrosive liquid used in the method comprises hydrochloric acid, nitric acid, sulfuric acid, water, copper sulfate and ferric trichloride. The macrograin corrosion method comprises the steps of firstly, placing a casting into a corrosion tank, pouring the corrosive liquid into the corrosion tank, and carrying out corrosion reaction for 20-30 minutes; after ending the corrosion reaction, taking out the casting, brushing away a black product left on the surface of the casting after the reaction is ended, then, flushing with clear water to obtain a macrostructure with a bright surface, and then, observing the macrostructure. According to the method, different corrosive media in a corrosive agent are utilized to simultaneously corrode a crystal boundary and a matrix or a strengthening phase at different speeds, and crystal grains with different orientations have remarkable symmetry errors, so that various surface defects in a single crystal blade are favorably shown.

Macrograin corrosion method for monocrystal high-temperature alloy casting containing Re and/or Ru

The invention discloses a cobalt-based high-temperature alloy for gas turbine guide blades and a preparation method and application thereof, and belongs to the technical field of casting cobalt-basedpolycrystal high-temperature alloys. The alloy comprises the chemical components of, by weight, 27.0-34.0% of Cr, 9.5-11.5% of Ni, 6.5-8.5% of W, 0.4-2.0% of Fe, 0-1.0% of Ta, 0.1-1.0% of Si, 0.1-1.0%of Mn, 0.15-0.35% of C, 0.005-0.015% of B, 0-0.2% of Y and the balance Co. A preparation process of an alloy casting comprises the steps that refining is conducted at the temperature of 1600+/-10 DEGC for 5-10 min, pouring is conducted at the temperature of 1420-1540 DEG C, and the shell temperature is 850+/-50 DEG C. The alloy has excellent high-temperature structure stability and oxidation resistance, further has high high-temperature mechanical properties, and is suitable for ground and naval gas turbine guide blade materials.

Cobalt-based high-temperature alloy for gas turbine guide blades and preparation method and application thereof

The invention discloses a high-strength thermal corrosion-resisting nickel base high-temperature alloy for a gas turbine, a preparation technology and application thereof, belonging to the technical field of metal materials. The high-strength thermal corrosion-resisting nickel base high-temperature alloy comprises the following chemical components in percentage by weight: 0.06-0.15% of C, 0.005-0.025% of B, 13.0-15.0% of Cr, 9.0-11.0% of Co, 0.5-0.99% of Mo, 4.3-5.2% of W, 3.0-3.6% of Al, 3.6-4.5% of Ta, 3.8-4.5% of Ti, 0-0.05% of Zr and the balance being Ni. The alloy has excellent thermal corrosion-resisting property and high-temperature strength, and good structure stability, is suitable for manufacturing hot end parts of the gas turbine and can be used for long time in a gas corrosionenvironment.

Shen Jian

Papers

Composite efficient ceramic core demolding process and special equipment thereof

Molten salt corrosion resistant nickel-based superalloy with excellent performance

Macrograin corrosion method for monocrystal high-temperature alloy casting containing Re and/or Ru

Cobalt-based high-temperature alloy for gas turbine guide blades and preparation method and application thereof

High-strength thermal corrosion-resisting nickel base high-temperature alloy for gas turbine and preparation technology and application thereof