Lightweight Heat-Resistant Material for Generator Gas Turbine

Abstract

The present invention overcomes brittleness of various beryllium alloys including beryllium intermetallic compounds and thereby provides a lightweight material for gas turbines. It's achieved by employing an alloy consisting essentially of an alloy of any one or more intermetallic compounds selected from the group of Be12M, but Be13M if M is Zr, Be10M, and Be17M, where M is any one or more metallic elements selected from the group of Ti, V, Mo, W, Zr, Nb and Ta.

Description

TECHNICAL FIELD [0001] The present invention relates to a material for gas turbines used for driving power generators or such, and more specifically to a lightweight heat-resistant material which enables raise in operation temperature of gas turbines as having high heat-resistance, and further accomplishes high energy conversion efficiency as being lightweight. BACKGROUND ART [0002] A gas turbine is known as a machine to extract driving force from hot gas obtained by combustion of fuel for driving power generators, jet engines and such. It is prominently effective in improvement of energy conversion efficiency to introduce the hot gas in higher temperature state into the gas turbine, namely, to raise operation temperature of the gas turbine. Further, to make rotary members such as rotor blades lighter in weight is also effective in improvement of the energy conversion efficiency. [0003] What are representative among materials in practical use for gas turbines are a group of nickel-b...

AI Technical Summary

Benefits of technology

[0006] The present invention is intended for overcoming brittleness of various beryllium alloys including beryllium intermetallic compounds and thereby providing a lightweight material for gas turbines, which has high heat-resistance and high-temperature corrosion resistance.

[0007] The present inventors had intently studied relations among phases and metallographic structures contained in beryllium alloys including beryllium intermetallic compounds and brittleness, heat-resistance and high-temperature corrosion resistance. As a result, the inventors had discovered a beryllium intermetallic compound phase of Be12M (when M is any one of Ti, V, Mo, W, Nb and Ta) or Be13Zr, and Be17M2 (M is any metallic element of Ti, V, Mo, W, Zr, Nb and Ta) is extremely brittle when existing as a single phase, whereas a composite phase in which two or more of Be12M or Be13Zr, Be10M, and Be17M are mixed as cast has ductility and is further given high heat-resistance and high-temperature corrosion resistance, and thereby reached the present invention of a lightweight material for generator gas turbines.

[0017] High heat-resistance and high-temperature corrosion resistance are given to beryllium alloys including beryllium intermetallic compounds, and thereby a lightweight material for generator gas turbines is provided.

Problems solved by technology

Titanium alloys have an advantage of relatively small relative density such as about 4.5 g / cm3, but also have problems in erosion-resistance and such.

However, it is known that control of impurities in matters including beryllium is difficult and various characteristics considerably change depending on the amount of impurities.

Moreover, as most of the materials including beryllium are brittle at the room temperature, methods for using the materials as structural materials are hardly ever known.

Further, because of the brittleness, forming and machining, such as cutting, per se are hard to be accomplished aside from the aforementioned HIP forming.

Therefore, industrial applicability of the beryllium alloys including beryllium intermetallic compounds has not been well known in the past.

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