1. Introduction 2. The physical metallurgy of nickel and its alloys 3. Single crystal superalloys for blade applications 4. Superalloys for turbine disc applications 5. Environmental degradation: the role of coatings 6. Summary and future trends.

The Superalloys: Fundamentals and Applications

Method and apparatus for embedding features and controlling material composition in a three-dimensional structure (130) are disclosed. The apparatus comprises a directed material deposition apparatus having a source (124) of a focused laser beam, a deposition head (11) being coordinated in a plurality of coordinate axes, a controlled atmosphere chamber (128), a control computer (129), a plurality of feedstock (126, 127), a design rendering a solid model including embedded features, and a positioning stage (16) with a substrate (19) disposed on it. Said deposition head (11) can be a multi-axis deposition head, with a volumetric powder feed unit, a rapid acting metering valve for powder feedstock control, a laser delivery system having an optical fiber with heat protection, a laser beam shutter dump assembly and a pluraltity of powder delivery nozzles comprising coaxial gas stream means for reduced powder dispersion. Material properties can be engineered by adjusting laser exposure, material deposition and material constants.

Forming structures from CAD solid models

Accident tolerant fuel cladding development: Promise, status, and challenges

A comprehensive and integrated review of thermal barrier coatings (TBCs) applied to turbine components is provided. Materials systems, processes, applications, durability issues, technical approaches and progress for improved TBC, and our understanding of the science and technology are discussed. Thermal barrier coating prime reliance and further advances have been hampered by TBC loss by particle impact and erosion in certain locations of the turbine blades. Accumulation of low melting eutectic containing calcia, magnesia, alumina and silica resulting in TBC spallation limits maximum surface temperature. Design methodologies to address durability and data scatter issues are discussed. Compositions, morphology, characteristics and performance data for new bonds to achieve longer TBC life are described. Further reduction in the thermal conductivity of the top layer to minimise the parasitic mass of the coating on the component is being sought via top layer composition and processing modifications a...

Thermal barrier coatings technology: critical review, progress update, remaining challenges and prospects

Continuous SiC fiber, CVI SiC matrix composites for nuclear applications: Properties and irradiation effects

Development of high-strength reaction-sintered silicon carbide

https://iopscience.iop.org/article/10.1016/S1468-6996(03)00009-3/pdf

EB-PVD process and thermal properties of hafnia-based thermal barrier coating

Design of Tungsten/Copper graded composite for high heat flux components

High velocity oxygen-fuel (HVOF) spraying system in open air has been established for producing the coatings that are extremely clean and dense. It is thought that the HVOF sprayed MCrAlY (M is Fe, Ni and/or Co) coatings can be applied to provide resistance against oxidation and corrosion to the hot parts of gas turbines. Also, it is well known that the thicker coating can be sprayed in comparison with any other thermal spraying systems due to improved residual stresses. However, thermal and mechanical properties of HVOF coatings have not been clarified. Especially, the characteristics of residual stress, that are the most important property from the view point of production technique, have not been made clear. In this paper, the mechanical properties of HVOF sprayed MCrAlY coatings were measured in both the case of as-sprayed and heat-treated coatings in comparison with a vacuum plasma sprayed MCrAlY coatings. It was confirmed that the mechanical properties of HVOF sprayed MCrAlY coatings could be improved by a diffusion heat treatment to equate the vacuum plasma sprayed MCrAlY coatings. Also, the residual stress characteristics were analyzed using a deflection measurement technique and a X-ray technique. The residual stress of HVOF coating was reduced by themore » shot-peening effect comparable to that of a plasma spray system in open air. This phenomena could be explained by the reason that the HVOF sprayed MCrAlY coating was built up by poorly melted particles.« less

Characteristics of MCrAlY Coatings Sprayed by High Velocity Oxygen-Fuel Spraying System

The present invention is directed to a method of preparing a composite material excellent in joint strength and heat conductivity, and more specifically to a method of preparing a composite material composed of a high-melting material W and low-melting material Cu. The method comprising a first step of forming pores in the high-melting material W, to obtain a substrate material having a porosity distribution, with a high porosity at at least one region of the surface of the substrate material and the porosity gradually decreasing outward from the region; and a second step of impregnating the low melting material Cu to the substrate material obtained in the first step from the region of the highest porosity gradually downward. The substrate material being formed to have a gradient distribution of a composite ratio of the high-melting material and the low-melting material.

Yoshiyasu Itoh

Papers

Development of high-strength reaction-sintered silicon carbide

EB-PVD process and thermal properties of hafnia-based thermal barrier coating

Design of Tungsten/Copper graded composite for high heat flux components

Characteristics of MCrAlY Coatings Sprayed by High Velocity Oxygen-Fuel Spraying System

Fabricating method of composite material