ECI Digital Archives

Title

Laser additive manufacturing of niobium silicide-based composites

Authors

Andrew Douglas, University of Leicester, UKFollow
Adam Allen, University of Leicester, UK
Huan Qian, University of Leicester, UK
Leandro Feitosa, University of Leicester, UK
Hongbiao Dong, University of Leicester, UK
Xin Lin, State Key Lab. of Solidification Processing, P.R. China
Weidong Huang, State Key Lab. of Solidification Processing, P.R. China

Conference Dates

July 17-21, 2016

Abstract

Niobium silicide-based composites, in the application of gas turbine blades, promise significant efficiency improvements compared to current Ni-based alloys. The higher temperature capability would allow the engine to run at a higher temperature than that of current alloys, increasing engine efficiency. Nb-Si based composites possess a lower density, due to the presence of ceramic phases such as Nb₅Si₃ and/or Nb₃Si. This would reduce the weight of the rotating blades. However, improvements in certain properties, such as ductility, room temperature toughness and oxidation resistance are needed. The alloy must also be cost effective to manufacture if niobium silicide systems are to reach their full potential.

This study focuses on the manufacturability aspect of the powder feeding laser additive manufacturing (LAM) process to engineering Nb-Si based alloy samples. A schematic drawing of LAM system is shown in Figure 1. In LAM process, CAD models of the components are constructed and sliced layer by layer for laser multilayer cladding, which directly forms the component shapes. LAM has the advantage of forming near-net shapes without the use of expensive cores and moulds for the reactive Nb-Si melt. Fine microstructure and even chemical composition distribution with reduced macro-segregation are obtained. With the use of power feeding system, new Nb-Si based alloys are LAMed with varying Ti, Si, Cr, Al, Hf, V concentrations. Microstructures and mechanical properties of the LAMed new alloys will be presented, the relationship between mechanical property, alloy chemistry and process variable will be analyzed and the challenges in powder feeding laser additive manufacturing of Nb-Si based composites will be reported.

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Recommended Citation

Andrew Douglas, Adam Allen, Huan Qian, Leandro Feitosa, Hongbiao Dong, Xin Lin, and Weidong Huang, "Laser additive manufacturing of niobium silicide-based composites" in "Beyond Nickel-Based Superalloys II", Chair: Dr Howard J. Stone, University of Cambridge, United Kingdom Co-Chairs: Prof Bernard P. Bewlay, General Electric Global Research, USA Prof Lesley A. Cornish, University of the Witwatersrand, South Africa Eds, ECI Symposium Series, (2016). https://dc.engconfintl.org/superalloys_ii/46