Effect of layer thickness on the high temperature mechanical properties of Al/SiC nanolaminates

THIN SOLID FILMS

卷:571

Article

Lotfian, S.¹  Mayer, C.²  Chawla, N.²  Llorca, J.^1,3  Misra, A.⁴  Baldwin, J. K.⁴  Molina-Aldareguia, J. M.¹ 

[1] IMDEA Mat Inst, Madrid 28906, Spain

[2] Arizona State Univ, Tempe, AZ 85287 USA

[3] Univ Politecn Madrid, Dept Mat Sci, ETS Ingenieros Caminos, E-28040 Madrid, Spain

[4] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

关键词: Metal-ceramic composite;    Multilayers;    Layer thickness;    Nanolaminate;    High temperature nanomechanics;    Nanoindentation;   

DOI  :  10.1016/j.tsf.2014.06.022

来源: Elsevier

【 摘 要 】

Composite laminates on the nanoscale have shown superior hardness and toughness, but little is known about their high temperature behavior. The mechanical properties (elastic modulus and hardness) were measured as a function of temperature by means of nanoindentation in Al/SiC nanolaminates, a model metal-ceramic nanolaminate fabricated by physical vapor deposition. The influence of the Al and SiC volume fraction and layer thicknesses was determined between room temperature and 150 degrees C and, the deformation modes were analyzed by transmission electron microscopy, using a focused ion beam to prepare cross-sections through selected indents. It was found that ambient temperature deformation was controlled by the plastic flow of the Al layers, constrained by the SiC, and the elastic bending of the SiC layers. The reduction in hardness with temperature showed evidence of the development of interface-mediated deformation mechanisms, which led to a clear influence of layer thickness on the hardness. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

Free