Laser forming of metal laminate composite materials

2003 ◽  
Author(s):  
S. P. Edwardson ◽  
G. Dearden ◽  
P. French ◽  
K. G. Watkins ◽  
W. J. Cantwell
Keyword(s):  
Composite Materials ◽  
Laminate Composite ◽  
Laser Forming

The Relation of the Interlaminar Fracture Toughness and the Acoustic Emission (Ae) under the Enf Test

2007 ◽  
Vol 353-358 ◽  
pp. 279-282
Author(s):  
Juho Kwak ◽  
Yu Seong Yun ◽  
Oh Heon Kwon
Keyword(s):  
Fracture Toughness ◽  
Composite Materials ◽  
Laminate Composite ◽  
High Strength ◽  
Light Weight ◽  
Interlaminar Fracture Toughness ◽  
Laminate Composites ◽  
Interlaminar Fracture ◽  
Good Corrosion Resistance ◽  
Enf Test

Recently, composite materials are used in many fields because their properties are high strength, high stiffness, and they have light weight, good corrosion resistance and good thermal conductivity. However, composite materials have relatively a lot of problems, especially delamination, compared with common materials such as a steel and aluminum, etc. Therefore, having the interlaminar fracture toughness for a laminate composite is important. In this study, the end notched flexure (ENF) specimens are employed in order to evaluate modeⅡ interlaminar fracture toughness for CFRP laminate composites. Three kinds of a/L ratio were applied to these specimens under the different pressure level. Also, we discuss the relation of crack growth and the interlaminar fracture toughness in terms of AE characteristics using ENF test.

Raman microprobe measurements of residual strains at the interfaces of Si on quartz

1987 ◽  
Vol 2 (6) ◽  
pp. 902-909 ◽  
Author(s):  
Y. M. Cheong ◽  
H. L. Marcus ◽  
F. Aclar
Keyword(s):  
Raman Spectroscopy ◽  
Composite Materials ◽  
Film Thickness ◽  
Small Volume ◽  
Laminate Composite ◽  
Stress Gradient ◽  
Recrystallization Process ◽  
Substrate Side ◽  
Raman Microprobe ◽  
Residual Strains

In order to quantitatively determine the residual stresses at the interfaces of laminate composite materials, a model involving exponential stress gradient in the substrate and no stress gradient in the film was derived. The measurements of residual strains at the Si/quartz interfaces using the Raman microprobe were compared to expected strains by the model. The model shows that a small volume of substrate near the interface about 2 times the film thickness was affected by the thermal mismatch of the two regions. Approximately 5–10 times higher residual strains were expected at the substrate-side interfaces compared to the measured results. This is explained by the experiments averaging along the probe thickness of about 10μm resolution. The recrystallization process of Si film by thermal annealing was also investigated using Raman spectroscopy.

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