Method for measuring shrinking percentage of inner cavity of hollow casting

Abstract

The invention discloses a method for measuring the shrinking percentage of an inner cavity of a hollow casting. The method is applied to measurement on the size change of the inner cavity of the blade in a manufacturing process of an air-cooling blade, aiming at solving the problem that the size change of the inner cavity of the blade cannot be measured in the prior art. The method comprises the following steps: firstly, designing an analog sample piece of the hollow casting, secondly, designing a core mold and an outer mold of the analog sample piece, and subsequently manufacturing the analog sample piece according to the manufacturing process of the blade, wherein quality control requirement on the analog sample piece is consistent with that on a real casting; after reinforcement at high temperature, measuring the three-dimensional sizes of a core of the prepared analog sample piece; and subsequently, reinforcing at low temperature, manufacturing a wax mold, manufacturing a molding shell, casting, cooling down and subsequently cutting the analog sample piece according to measurement lines, measuring the inner cavity of the casting, and finally measuring and calculating the shrinkage percentage. By adopting the method, the precision of the size of the inner cavity of a turbine blade is ensured, and the pass percent of the casting is increased.

Description

technical field [0001] The invention belongs to a method for measuring the shrinkage rate, and relates to a method for measuring the shrinkage rate of the inner cavity of a hollow casting. Background technique [0002] The urgent need of modern aero-engines is to improve the working performance of gas turbine engines. Firstly, the gas temperature of the turbine is increased. However, due to the limitation of the melting point of metals, the high-temperature capability of blades on alloy materials is currently close to the limit. Therefore, the gas temperature of blades is continuously improved. The cold structure is to improve the cooling efficiency, which has become the goal pursued by the designers and manufacturers of turbine blades at the same time. [0003] One of the key manufacturing technologies of modern aero-engine "air-cooled blades" is the control of the inner cavity size of the blade, and the inner cavity size is guaranteed by the ceramic core. The final size of...

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Problems solved by technology

[0002] The urgent need of modern aero-engines is to improve the working performance of gas turbine engines. Firstly, the gas temperature of the turbine is increased. However, due to the limitation of the melting point of metals, the high-temperature capability of blades on alloy materials is currently close to the limit. Therefore, the gas temperature of blades is continuously improved. The cold structure is to improve the cooling efficiency, which has become the goal pursued by the designers and manufacturers of turbine blades at the same time.

[0003] One of the key manufacturing technologies of modern aero-engine "air-cooled blades" is the control of the inner cavity size of the blade, and the inner cavity size is guaranteed by the ceramic core. The final size of the ceramic core depends on the precision casting process and the shape. The accuracy of the shrinkage rate determined during the design of the core mold directly affects the size of the inner cavity of the blade, that is, the cooling effect of the air-cooled blade and the pass rate of the wall thickness of the casting, and how the size of the casting of the ceramic core changes during the pouring process cannot be measured Yes, so the shrinkage rate of this process has been inferred by experience, and the accuracy of the value cannot be guaranteed, resulting in a large gap in the size of the ceramic core

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