Super-cooling nickel base high-temperature alloy purifying agent and preparation method thereof

Abstract

The invention discloses a super-cooling DZ125 high-temperature alloy purifying agent and a preparation method thereof. The method comprises the following steps: in percentage by mass, weighing 40 to 50 percent of calcium fluoride, 16 to 30 percent of aluminum fluoride, 10 to 15 percent of cryolite, 5 to 8 percent of sodium chloride, 5 to 8 percent of potassium chloride, 4 to 6 percent of calcium oxide and 1 to 2 percent of rare-earth compound; putting the potassium chloride, the sodium chloride, the cryolite, the calcium fluoride, the aluminum fluoride and the calcium oxide into a crucible, stirring the mixture evenly, and raising the temperature to between 1,050 and 1,100 DEG C and keeping the temperature for 3 to 4 hours; then breaking sintered blocky molten salt, milling the broken molten salt into powder in a ball mill, and screening the powder with a sieve selected from No. 20 to No. 40; and adding the rare-earth compound into the powder, mixing the mixture evenly by the ball mill, and filling the mixture into a drier for standby after preparation. The super-cooling DZ125 high-temperature alloy purifying agent can effectively adsorb and dissolve oxidized inclusions, and has the advantages of good chemical stability, less harmful gas, simple operation process, convenient adding and low price.

Description

technical field [0001] The invention relates to a purifier and a preparation method thereof, which is specially used for the supercooling and purification research of DZ125 nickel-based superalloy, and belongs to the technical field of metal materials and metallurgy. [0002] Background technique [0003] As an advanced material preparation and processing technology, deep subcooling and rapid solidification can reduce the degree of structure segregation, homogenize the composition, and significantly refine the grains. Finding an effective purging agent to remove the heterogeneous core in the melt or inhibit the heterogeneous nucleation of the heterogeneous core to obtain a large degree of supercooling is the key to the study of deep supercooling. [0004] In recent years, the research on deep supercooling and rapid solidification of bulk liquid metals has been very active, and great progress has been made, but there are still the following problems: (1) The research on deep ...

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Problems solved by technology

[0003]In recent years, the research on deep subcooling and rapid solidification of large-volume liquid metals has been very active, and great progress has been made, but there are still the following problems: (1) deep supercooling Research mainly focuses on inactive metals and alloys such as Ni, Cu, Fe, etc., and there are few studies on multi-element superalloys with strong engineering properties; O3, Na2B4O7·10H2O and Na 2SiO3 and so on are heated and dehydrated in a certain proportion. This purifying agent is mainly used for the supercooling of inactive metals; The materials used are relatively complex in composition, and most of them contain a large amount of active elements such as Al, Ti and C, B, Hf and other grain boundary strengthening elements. As the content of Al and Ti increases, the high-temperature strength of the alloy increases.

Adopt existing composite molten salt purifying agent at present, as described in document " purification influence factor and approach of supercooled DD3 single crystal superalloy " (Liu Feng, Cai Yu etc., casting, 2000,49 (6)), to DZ125 superalloy is also difficult to obtain a large degree of undercooling in experiments, so it is impossible to carry out research on the microstructure evolution of DZ125 superalloy in a wide range of undercooling

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