Abstract: A tip plug is capped on a boss section so as to fit to a hole which is used for detaching a core which is formed in a blade tip section of the gas turbine blade. A butt-section T is melted so as to form a butt-welding section by using a YAG laser beam. Also, parameters such as an interval between the butt-section T, a member for forming the tip plug, condition for a laser welding operation, and a defocus position of the laser beam are optimized.

Abstract: A method and apparatus automatically repairs cracks produced in a member to be repaired. A wide field image is obtained by photographing the whole surface of a blade 31 or the like in a wide field view by a remote camera 11 and the position of cracks on the surface of the blade is obtained as a rough position information of the cracks by processing the image of wide field view. Then the cracks are photographed in a narrow field view at the predetermined spacing along the cracks based on the rough position information by a light section method. The narrow field images are processed to obtain the position, width, and depth of the crack at each predetermined spacing, which compose crack data at the series of points, and the cracks are repaired based on the crack data at the series of points.

Abstract: A welding method forms a molten build-up portion on a base material that is any one of a single crystal material and a unidirectionally solidified crystal material. The method includes forming a plurality of build-up portions on the base material while maintaining a predetermined gap between adjacent build-up portions; and forming a build-up portion in each of the predetermined gaps.

Abstract: The present invention provides a gas turbine in which a proper clearance is kept between a rotor blade and a shroud for a long period of time from the operation start, so that damage to the rotor blade is less liable to occur. In a turbine portion of the gas turbine in accordance with the present invention, the rotor blade and the shroud face each other. At the tip end of the rotor blade is formed an abrasive layer, and on the inner peripheral surface of the shroud is formed a heat insulating layer. The abrasive layer is formed of a matrix and many abrasive particles dispersed in the matrix. The abrasive particles include protruding particles protruding from the matrix and embedded particles embedded in the matrix. In initial sliding of the rotor blade and the shroud at the early stage of operation, the inner peripheral surface of the shroud is ground by the protruding particles. After the protruding particles have disappeared, the inner peripheral surface of the shroud is ground by the embedded particles.

Abstract: The present invention provides an abrasion-resistant coating which has high oxidation resistance and durability and can be applied easily at a low cost. The abrasion-resistant coating in accordance with the present invention is formed at the tip end of a base material forming a gas turbine blade. The abrasion-resistant coating at the tip end has a thickness of 300 microns. On the tip end, hard particles H consisting of CBN are fixed in a bond coating formed by heating, melting, and solidification of a mixture of a brazing filler metal and M—Cr—Al—Y (M designates a metal element such as Co and Ni). The hard particles H are Ni and Co coated to improve wettability relative to the brazing filler metal, and are arranged so that some of them are partially protruded from the surface of bond coating to exhibit the grindability.

Abstract: The method of the present invention comprises a steps of performing nickel strike plating onto a base material, thereby forming a first plating layer, performing nickel plating, in which alloy particles containing at least Cr, Al and Y are dispersed, onto the first plating layer, thereby forming a second plating layer, performing nickel plating, in which alloy particles containing at least Cr, Al and Y and hard particles are dispersed, on the second plating layer, thereby forming a third plating layer, performing plating, in which alloy particles containing at least Cr, Al and Y are dispersed, onto the third plating layer, thereby forming a fourth plating layer such that the hard particles of the third plating layer are partly exposed, and performing intermediate heating process to the plating layers to diffuse the alloy particles throughout the plating layers, thereby forming an alloy layer.

Abstract: A tip plug is capped on a boss section so as to fit to a hole which is used for detaching a core which is formed in a blade tip section of the gas turbine blade. A butt-section T is melted so as to form a butt-welding section by using a YAG laser beamthere; thus, the hole is plugged by the tip plug. Also, parameters such as an interval between the butt-section T, a member for forming the tip plug, condition for a laser welding operation, and a defocus position of the laser beam are optimized. By doing this, it is possible to control the entering heat amount and prevent the solidification cracking and the liquation cracking reliably. Furthermore, it is possible to melt and weld the butt-welding section more strongly by using a laser having a narrow bead width; thus, it is possible to improve the manufacturing process efficiently and produce a product in uniform quality repeatedly.

Abstract: The present invention provides a gas turbine in which a proper clearance is kept between a rotor blade and a shroud for a long period of time from the operation start, so that damage to the rotor blade is less liable to occur. In a turbine portion of the gas turbine in accordance with the present invention, the rotor blade and the shroud face each other. At the tip end of the rotor blade is formed an abrasive layer, and on the inner peripheral surface of the shroud is formed a heat insulating layer. The abrasive layer is formed of a matrix and many abrasive particles dispersed in the matrix. The abrasive particles include protruding particles protruding from the matrix and embedded particles embedded in the matrix. In initial sliding of the rotor blade and the shroud at the early stage of operation, the inner peripheral surface of the shroud is ground by the protruding particles. After the protruding particles have disappeared, the inner peripheral surface of the shroud is ground by the embedded particles.

Abstract: At first, a brazing filler metal sheet is prepared (step S1). The brazing filler metal sheet comprises a brazing filler metal layer, a sticking material layer, and a released paper. The brazing filler metal layer comprises a brazing filler metal. A coating material layer is laminated on the brazing filler metal layer (step S2). The coating material layer comprises a mixture of coating material particles and a binder. As the coating material particles, MCrAlY particles and abrasive particles (cubic boron nitride particles or the like) are used. The coating material layer is then dried (step S3), and the brazing filler metal sheet is cut (step S4), and adhered to a rotor blade (step S5). The rotor blade is heated (step S6), to melt the brazing filler metal. The brazing filler metal gets wet as a liquid phase around the MCrAlY particles, and diffuses due to the heat treatment holding process. A solidified layer is then formed by cooling (step S7).

Abstract: The present invention provides an abrasion-resistant coating which has high oxidation resistance and durability and can be applied easily at a low cost. The abrasion-resistant coating in accordance with the present invention is formed at the tip end of a base material forming a gas turbine blade. The abrasion-resistant coating at the tip end has a thickness of 300 microns. On the tip end, hard particles H consisting of CBN are fixed in a bond coating formed by heating, melting, and solidification of a mixture of a brazing filler metal and M-Cr—Al—Y (M designates a metal element such as Co and Ni). The hard particles H are Ni and Co coated to improve wettability relative to the brazing filler metal, and are arranged so that some of them are partially protruded from the surface of bond coating to exhibit the grindability.

Abstract: When a three-dimensional structure is formed by welding a plurality of members, accurate welding can be performed matching the three-dimensional shape. The teaching data consisting of the three-dimensional position at each of the welding points determined on each of the welding lines at a predetermined spacing on the basis of the design data of the three-dimensional structure is stored in a memory 18. A laser slit light sensor (a laser slit light emitting section 12 and a CD camera 13) is controlled by a total controller 17 via a camera controller 14 to photograph the welding point in order to obtain the image data of the welding point. An image processing apparatus 16 processes the image data to determine the amount of deviation from the design data of welding points.

Abstract: The invention provides a method and apparatus for automatically repairing the cracks produced in the member to be repaired. A wide field image is obtained by photographing the whole surface of a blade 31 or the like in a wide field view by a remote camera 11 and the position of cracks on the surface of the blade is obtained as a rough position information of the cracks by processing the image of wide field view. Then, the cracks are photographed in a narrow field view at the predetermined spacing along the cracks based on the rough position information by light section method. The narrow field images are processed to obtain the position, width, and depth of the crack at each predetermined spacing, which compose crack data at-the series of points, and the cracks are repaired based on the crack data at the series of points.