Abstract: A piece of a titanium-base alloy having an elevated temperature phase transformation is diffusion bonded to a second phase at an accelerated rate or reduced temperature, as compared with conventional diffusion bonding, by manipulating the phase transformation with an alloying element that can be readily introduced into, and removed from, the titanium piece. The introduction of hydrogen into the titanium alloy reduces the temperature of the phase transformation. The titanium alloy can be repeatedly cycled through the phase transformation before or during bonding, by the introduction and removal of hydrogen, to reduce the flow stress through transformation plasticity. Alternatively, the titanium alloy may be loaded with hydrogen to reduce the phase transformation temperature, increasing the fraction of the more deformable phase and then reducing the flow stress of the alloy at the diffusion bonding temperature.

Abstract: Cast titanium alloys and a method of heat treating the alloys in order to obtain fatigue and mechanical properties comparable to wrought titanium is disclosed. The heat treatment is practiced by solution heat treating a cast titanium article above its beta transus, rapidly cooling, stabilizing at a temperature within the alloy's alpha/beta phase range, and finally aging the article to achieve the desired properties.

Abstract: Plasma flame sprayed ceramic thermal barrier coatings on metal substrates are treated to make the coatings resistant to damage from thermal cycling. The coating and substrate are heated to a temperature in the range of 820.degree.-1150.degree. C. then are quenched in a medium capable of producing a surface heat flux of at least 1.3.times.10.sup.5 watts/m.sup.2. This causes creation of a fine network of cracks extending from the surface of the coating to the surface of the substrate whereby during thermal cycling, buildup of damaging stresses at the coating-substrate interface is avoided.

Abstract: A coated article and method for producing the coated article are described. The article is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer is applied to the article to be protected and a columnar grain ceramic is applied by vapor deposition to the MCrAlY coated article. An alumina layer which exists between the MCrAlY layer and the columnar ceramic layer provides for the adherence of the columnar layer to the MCrAlY layer. An important feature of the invention is that the interface between the MCrAlY layer and the alumina layer has a low surface roughness and this greatly improves the columnar ceramic layer adherence.

Abstract: A coated article and method for producing the coated article are described. The article is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer is applied to the article to be protected and a columnar grain ceramic is applied by vapor deposition to the MCrAlY coated article. An alumina layer which exists between the MCrAlY layer and the columnar ceramic layer provides for the adherence of the columnar layer to the MCrAlY layer. An important feature of the invention is that the interface between the MCrAlY layer and the alumina layer has a low surface roughness and this greatly improves the columnar ceramic layer adherence.

Abstract: Disclosed is a nickel base alloy of the gamma-gamma prime type, the composition of which is controlled, to provide a gamma matrix phase in which solid solution hardener elements are minimized, to less than 12.5 weight percent. Preferably, the alloy consists essentially by weight percent of 0.25-9Al, 1-4Ti, 2-6Cb, 0.01-0.1C, at least one material selected from the group consisting by weight percent of 0-6Co, 0-6Mo, 2-7.5Cr, 0-2.5Hf and mixtures thereof, balance nickel. The gamma prime fraction in a heat treated article is in the range 10-45 volume percent. The stacking fault energy is preferably in the range 80-120 ergs/cm.sup.2. A gas turbine engine disc made of the material exhibits a three fold increase in fatigue life in the 550-750.degree. C. range, as compared to discs made of typical superalloys in current use, while retaining comparable tensile and stress rupture strength.

Abstract: A coated article and method for producing the coated article are described. The article is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer is applied to the article to be protected and a columnar grain ceramic is applied by vapor deposition to the MCrAlY coated article. An alumina lyaer which exists between the MCrAlY layer and the columnar ceramic layer provides for the adherence of the columnar layer to the MCrAlY layer. An important feature of the invention is that the interface between the MCrAlY layer and the alumina layer has a low surface roughness and this greatly improves the columnar ceramic layer adherence.