Effect of continuous cooling rate on the precipitation of gamma prime in nickel-based superalloys

Journal Article · Tue Aug 15 04:00:00 EDT 1995 · Scripta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-716X(95)00234-M· OSTI ID:103570

Klepser, C A ^[1]

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1. Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering

Many components in gas turbine engines are subjected to high temperatures and stresses. Currently, nickel-base superalloys supply the necessary mechanical and thermal properties for most high temperature engine applications. These alloys derive their unique strength characteristics from a dispersion of fine second-phase precipitate denoted {gamma}{prime} which has a composition Ni{sub 3}(Al,Ti). The finest particles are called cooling {gamma}{prime} because they form upon quenching. Coarse, primary {gamma}{prime} is also often present in the matrix. The volume fraction modified model is the best model for predicting cooling {gamma}{prime} size for isothermal heat treatments. For predicting {gamma}{prime} size for continuous cooling, no improvements on the basic model were seen because all the corrective efforts were based on coarsening theory alone and the evidence points to the existence of another mechanism in addition to coarsening. This mechanism is proposed to be the cooling rate dependent addition of {gamma}{prime} formers to existing particles directly from solution. A method to account for these additions needs to be established to predict cooling {gamma}{prime} size for continuous cooling.

• OSTI ID: 103570
• Journal Information: Scripta Metallurgica et Materialia, Journal Name: Scripta Metallurgica et Materialia Journal Issue: 4 Vol. 33; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
HEAT TREATMENTS
INTERMETALLIC COMPOUNDS
LIQUID METALS
MATHEMATICAL MODELS
METALLURGICAL EFFECTS
NICKEL BASE ALLOYS
NUCLEATION
PARTICLE SIZE
PHASE STUDIES
PRECIPITATION
TITANIUM ALLOYS