The Experts below are selected from a list of 21195 Experts worldwide ranked by ideXlab platform

Keith Ridgway - One of the best experts on this subject based on the ideXlab platform.

  • tool life and surface integrity aspects when drilling and hole making in inconel 718
    Journal of Materials Processing Technology, 2008
    Co-Authors: A R C Sharman, A Amarasinghe, Keith Ridgway
    Abstract:

    Abstract Drilling is one of the most important processes in aerospace manufacture and is often the last operation performed. When combined with the fact that holes amplify any in service stresses a significant demand for high surface integrity and production process security is created. In contrast to other machining processes there are relatively few publications regarding the drilling of Nickel-Based Superalloys. Following a brief review on the general machinability of Inconel 718 a series of experiments examining the tool life/wear of various commercially available drills, recommended for use on Nickel-Based Superalloys, is detailed. In addition a comparison of the resultant hole integrity produced by drilling alone is compared to that obtained using reaming and a relatively new technique of mill boring. The main conclusion is that when using commercially available drills the resulting hole quality is not sufficient to meet the requirements of the aerospace industry and therefore secondary processing is required. Mill boring with a standard milling tool appears to have significant potential for improving productivity and reducing costs compared to reaming.

  • an analysis of the residual stresses generated in inconel 718 when turning
    Journal of Materials Processing Technology, 2006
    Co-Authors: A R C Sharman, J I Hughes, Keith Ridgway
    Abstract:

    Abstract Inconel 718 is one of a family of nickel based Superalloys that are used extensively by the aerospace industry in the hot sections of gas turbine engines. The literature detailing the effects of varying operating parameters on tool life when machining nickel based Superalloys is comprehensive, however, relatively little of this data refers to their effects on machined workpiece surface integrity and residual stress generation. Greater knowledge of the effects of operating parameters on surface integrity is critical to the acceptance of new cutting tool materials, tool geometries and strategies. The paper initially reviews prior work on the surface integrity achieved when turning Inconel 718. Following on from this a series of experiments evaluating the effects of varying cutting tool material, geometry, wear level and operating parameters are detailed. The results show that the largest influence on surface integrity was tool wear. Cutting with a worn tool resulted in greater microstructural deformation, microhardness changes and high surface tensile stresses. High tensile stresses were also formed in the surface layer when cutting with a coated tool, while cutting with an uncoated tungsten carbide insert at the same operating parameters produced deep compressive stresses beneath a reduced tensile layer.

A R C Sharman - One of the best experts on this subject based on the ideXlab platform.

  • tool life and surface integrity aspects when drilling and hole making in inconel 718
    Journal of Materials Processing Technology, 2008
    Co-Authors: A R C Sharman, A Amarasinghe, Keith Ridgway
    Abstract:

    Abstract Drilling is one of the most important processes in aerospace manufacture and is often the last operation performed. When combined with the fact that holes amplify any in service stresses a significant demand for high surface integrity and production process security is created. In contrast to other machining processes there are relatively few publications regarding the drilling of Nickel-Based Superalloys. Following a brief review on the general machinability of Inconel 718 a series of experiments examining the tool life/wear of various commercially available drills, recommended for use on Nickel-Based Superalloys, is detailed. In addition a comparison of the resultant hole integrity produced by drilling alone is compared to that obtained using reaming and a relatively new technique of mill boring. The main conclusion is that when using commercially available drills the resulting hole quality is not sufficient to meet the requirements of the aerospace industry and therefore secondary processing is required. Mill boring with a standard milling tool appears to have significant potential for improving productivity and reducing costs compared to reaming.

  • an analysis of the residual stresses generated in inconel 718 when turning
    Journal of Materials Processing Technology, 2006
    Co-Authors: A R C Sharman, J I Hughes, Keith Ridgway
    Abstract:

    Abstract Inconel 718 is one of a family of nickel based Superalloys that are used extensively by the aerospace industry in the hot sections of gas turbine engines. The literature detailing the effects of varying operating parameters on tool life when machining nickel based Superalloys is comprehensive, however, relatively little of this data refers to their effects on machined workpiece surface integrity and residual stress generation. Greater knowledge of the effects of operating parameters on surface integrity is critical to the acceptance of new cutting tool materials, tool geometries and strategies. The paper initially reviews prior work on the surface integrity achieved when turning Inconel 718. Following on from this a series of experiments evaluating the effects of varying cutting tool material, geometry, wear level and operating parameters are detailed. The results show that the largest influence on surface integrity was tool wear. Cutting with a worn tool resulted in greater microstructural deformation, microhardness changes and high surface tensile stresses. High tensile stresses were also formed in the surface layer when cutting with a coated tool, while cutting with an uncoated tungsten carbide insert at the same operating parameters produced deep compressive stresses beneath a reduced tensile layer.

Jiarong Li - One of the best experts on this subject based on the ideXlab platform.

  • deformation and recrystallization of single crystal nickel based Superalloys during investment casting
    Journal of Materials Processing Technology, 2015
    Co-Authors: Zhonglin Li, Jichun Xiong, Qingyan Xu, Jiarong Li
    Abstract:

    Abstract A semi-quantitative, macroscopic, phenomenon-based, thermo-elastic–plastic model was developed to predict the final plastic strains of single crystal Nickel-Based Superalloys by considering their orthotropic mechanical properties. Various cases were considered and simulated to investigate the basic factors that influence the final plasticity. Thermo-mechanical numerical analysis was conducted to predict the recrystallization sites of simplified cored rods, with the results in good agreement with the experimental results. These hollowed rods with thin walls showed an increased propensity for recrystallization. The geometric features, especially stress concentration sites, are more significant to the induced plasticity than the material's orientation or shell/core materials. This paper also attempts to provide useful suggestions, such as introducing filets, to avoid causing plastic strains during the casting process that induce recrystallization.

Xinhua Wu - One of the best experts on this subject based on the ideXlab platform.

B. Warnes - One of the best experts on this subject based on the ideXlab platform.

  • Extreme Temperature Coatings for Future Gas Turbine Engines
    Journal of Engineering for Gas Turbines and Power, 2014
    Co-Authors: Mary Anne Alvin, K. Klotz, B. Mcmordie, Di Zhu, Brian Gleeson, B. Warnes
    Abstract:

    The National Energy Technology Laboratory-Regional University Alliance (NETL-RUA) has been developing extreme temperature coating systems that consist of a diffusion barrier coating (DBC), a low-cost wet slurry bond coat, a commercial yttria stabilized zirconia (YSZ) thermal barrier coating (TBC), and an extreme temperature external coating that are deposited along the surface of Nickel-Based Superalloys and single crystal metal substrates. Thermal cyclic testing of these multilayer coatings was conducted in steam-containing environments at temperatures ranging between 1100 and 1550°C. This paper discusses the response of these materials during bench-scale testing, and their potential use in advanced H- and J-class land-based gas turbine engines. © 2014 by ASME.