Abstract: An article protected by a protective coating includes a substrate made of a first nickel-base superalloy substrate material that is susceptible to the formation of a secondary reaction zone when overlaid by a diffusion aluminide coating or an aluminide overlay coating. A protective coating including a deposited coating at the substrate surface. The deposited coating is a second nickel-base superalloy different from the first nickel-base superalloy and which does not produce a secondary reaction zone when interdiffused with the first nickel-base superalloy. In one version, the deposited coating has a nominal composition, in weight percent, of about 3.1 percent cobalt, about 7.6 percent chromium, about 7.8 percent aluminum, about 5.45 percent tantalum, about 3.85 percent tungsten, about 1.65 percent rhenium, about 0.02 percent carbon, about 0.016 percent hafnium, about 0.015 percent boron, about 0.5 percent silicon, balance nickel and incidental impurities.

Abstract: An article protected by a protective coating includes a substrate made of a first nickel-base superalloy substrate material that is susceptible to the formation of a secondary reaction zone when overlaid by a diffusion aluminide coating or an aluminide overlay coating. A protective coating including a deposited coating at the substrate surface. The deposited coating is a second nickel-base superalloy different from the first nickel-base superalloy and which does not produce a secondary reaction zone when interdiffused with the first nickel-base superalloy. In one version, the deposited coating has a nominal composition, in weight percent, of about 3.1 percent cobalt, about 7.6 percent chromium, about 7.8 percent aluminum, about 5.45 percent tantalum, about 3.85 percent tungsten, about 1.65 percent rhenium, about 0.02 percent carbon, about 0.016 percent hafnium, about 0.015 percent boron, about 0.5 percent silicon, balance nickel and incidental impurities.

Abstract: A laser shock peening system includes an apparatus and method that senses a thickness of laser transparent confinement media flow, such as water. In one embodiment, the apparatus indicates a proper thickness, in another embodiment, the apparatus controls the flow rate of the confinement media using signals from probes of the apparatus. A first probe is used to sense a predetermined minimum thickness and another embodiment further includes a second probe to indicate a predetermined maximum thickness of the confinement media.

Abstract: A test coupon is formed from a metallic strip having opposite first and second sides that generally define a plane of the strip and the strip includes a laser shock peened patch of the strip that has first and second laser shock peened surfaces on the first and second sides, respectively, first and second laser shocked regions having deep compressive residual stresses imparted by the laser shock peening extending into the strip from the first and second laser shock peened surfaces, respectively, and a deflection of a portion of the strip from a position of the portion before the laser shock peening. The deflection is formed by the laser shock peening such that at least a part and preferably substantially all of the deflection lies in the plane and the test coupon preferably includes an indicating means to indicate the deflection.

Abstract: The present invention provides a metallic article with at least one laser shock peened surface on at least a portion of the article and a plurality of volumetrically spaced apart laser shock peened protrusions extending into the article from said laser shock peened surface wherein the protrusions have deep compressive residual stresses imparted by laser shock peening (LSP). The invention may be further characterized by spaced apart circular laser beam spots on the surface from which the laser shock peened protrusions extend into the article such that the spots do not overlap.

Abstract: A method of laser shock peening a hard metallic article by firing a laser beam on different points of a laser shock peened surface of at least a portion of the article using a laser beam with sufficient power to vaporize material on the surface around laser beam spots formed by the laser beam at the points on the surface, flowing a curtain of water over the surface upon which the laser beam is firing, and firing the laser beam so as to form a plurality of volumetrically spaced apart laser shock peened protrusions extending into the article from the spots such that the protrusions have deep compressive residual stresses imparted by laser the laser beam. The surface may first be coated with an ablative material which the laser beam vaporizes and the method may be an on the fly method of laser shock peening which further includes continuously moving the article while continuously firing a stationary laser beam which repeatably pulses between relatively constant periods.

Abstract: A method for quality assurance of a laser process and more particularly a laser shock peening process that uses a test coupon having a deflection formed by a laser firing. The test coupon is from a metallic strip having opposite first and second sides that generally define a plane of the strip and the strip includes a laser shock peened patch of the strip that has first and second laser shock peened surfaces on the first and second sides, respectively, first and second laser shocked regions having deep compressive residual stresses imparted by the laser shock peening extending into the strip from the first and second laser shock peened surfaces, respectively, and a deflection of a portion of the strip from a position of the portion before the laser shock peening. The deflection is formed by the laser shock peening such that at least a part and preferably substantially all of the deflection lies in the plane of the strip and the test coupon preferably includes an indicating means to indicate the deflection.

Abstract: A single-crystal article having a thermal barrier coating on a surface thereof, and a method for processing the article so as to promote the life of the coating. As a result of its single-crystal microstructure, the article is characterized by having been unidirectionally solidified along a primary crystallographic direction, and secondary crystallographic directions that are normal to the primary crystallographic direction. Improved spallation resistance of the coating is achieved by selectively orienting the secondary crystallographic direction with respect to a direction normal to a life-limiting surface region of the thermal barrier coating.

Abstract: An improved thermal switch permitting large temperature excursions beyond the design closure temperature without stressing the switch material beyond its elastic limits. It combines a bimetal portion with a spring portion through which movement is transmitted, the former providing sufficient deformation for closure at design temperature, and the latter accommodating excess deformation beyond closure caused by high temperature. It is particularly useful in metal halide lamps having gas filled outer envelopes and requiring shorting of an auxiliary starting electrode to the adjacent main electrode during operation.