Abstract: A heat treatment technique may include heating an alloy component to a temperature above a transition temperature of the alloy or heating an alloy component to a temperature below the transition temperature of the alloy. The heat treatment technique further may include cooling a first portion of the alloy component at a first cooling rate, and cooling a second portion of the alloy component at a second cooling rate different than the first rate. The first cooling rate may result in formation of a plurality of first precipitate phase domains comprising a first average size in the first portion, and the second cooling rate may result in formation of a plurality of second precipitate phase domains comprising a second average size in the second portion. The average size of the first precipitate phase domains may be different than the average size of the second precipitate phase domains.

Abstract: A mixture and technique for coating an internal surface of an article is generally described. In one aspect, a method includes introducing a mixture comprising an aluminum source and an organo halocarbon activator into an internal cavity of an article. In some embodiments, the method may further include heating the article and the mixture to a temperature sufficient to form an aluminum halide, which deposits on a surface of the internal cavity to form a coated article. In further embodiments, the method may also include depositing on an external surface of the article a first layer comprising Pt, Si, and a reactive element selected from the group consisting of Hf, Y, La, Ce, Zr, and combinations thereof, and depositing a second layer comprising Al on the first layer to form an alloy including a ?-Ni+??-Ni3Al phase constitution, where the second layer is deposited with the organo halocarbon activator.

Abstract: A coating including a bond layer deposited on a substrate. The bond layer includes a rare earth silicate and a second phase, the second phase including at least one of silicon, silicides, alkali metal oxides, alkali earth metal oxides, glass ceramics, Al2O3, TiO2, Ta2O5, HfO2, ZrO2, HfSiO4, ZrSiO4, HfTiO4, ZrTiO4, or mullite. The coating may provide thermal and/or environmental protection for the substrate, especially when the substrate is a component of a high-temperature mechanical system.

Abstract: A coating including a CMAS-resistant layer with a rare earth oxide. The CMAS-resistant layer is essentially free of zirconia and hafnia, and may further include at least one of alumina, silica, and combinations thereof.

Abstract: A method including depositing a powder on a substrate to form a first layer thereon, wherein the layer includes a Pt group metal, Si and reactive element selected from the group consisting of Hf, Y, La, Ce, Zr, and combinations thereof. Deposited on the first layer is a second layer including Al to form a coating with a ?-Ni+???Ni3Al phase constitution. In preferred embodiments, the second layer is deposited with an organo halocarbon activator.