Fracture toughness of germanium determined with the Vickers indentation technique

1988 ◽  
Vol 7 (8) ◽  
pp. 895-896 ◽  
Author(s):  
P. Lemaitre
2009 ◽  
Vol 65 ◽  
pp. 47-52 ◽  
Author(s):  
N. López-Perrusquia ◽  
Ivan Campos-Silva ◽  
José Martínez-Trinidad ◽  
A. Avilés ◽  
E. Alvárez-Castañeda ◽  
...  

The fracture toughness of AISI H13 borided steel and the strength adhesion of the coated system were estimated in the present work. The formation of the layers was carried out by the powder pack boriding process at 1273 K with 8 h of treatment. The fracture toughness (KC) of the layer is estimated at 25 and 45 m from the surface using four different Vickers indentation loads. The KC values were estimated by the extension of Palmqvist cracks parallel and perpendicular to the surface obtained at the indentation corners. The adherence of the layer/substrate was evaluated in qualitative form through the Rockwell-C indentation technique. The results obtained by both techniques, show, in first instance, that the fracture toughness of the boride layer can be expressed in the form (KC) (π/2) > (KC) > (KC) (0). Also, high delamination is obtained around the Rockwell-C indentation prints that denote poor adhesion in the coating-substrate interface.


2007 ◽  
Vol 280-283 ◽  
pp. 1471-1474
Author(s):  
Zhi Xiong ◽  
Gang Wang ◽  
Wan Jiang

The room temperature fracture toughness and the high temperature DBTT of MoB particle-reinforced MoSi2 composites were investigated using Vickers indentation technique and MSP testing method, respectively. Modified Small Punch (MSP) test is a method for evaluation of mechanical properties using very small specimens, and it’s appropriate for the determination of strength and DBTT. It was found that the approximate fracture toughness of the composite is 1.3 times that of monolithic MoSi2, and its DBTT is 100°C higher than that of monolithic MoSi2 materials. Cracks deflection is a probable mechanism responsible for this behavior.


2007 ◽  
Vol 40 (22) ◽  
pp. 7090-7096 ◽  
Author(s):  
Zhijian Yin ◽  
Shunyan Tao ◽  
Xiaming Zhou ◽  
Chuanxian Ding

2008 ◽  
Vol 385-387 ◽  
pp. 893-896
Author(s):  
Kyung Woo Lee ◽  
Hyun Uk Kim ◽  
Sang Wook Park ◽  
Jung Suk Lee ◽  
Kwang Ho Kim ◽  
...  

This study focused on the determination of fracture toughness by instrumented indentation technique. A theoretical model to estimate the fracture toughness of ductile materials is proposed and used to verify those results. Modeling of IIT to evaluate fracture toughness is based on two main ideas; the energy input up to characteristic fracture initiation point during indentation was correlated with material’s resistance to crack initiation and growth, and this characteristic fracture initiation point was determined by concepts of continuum damage mechanics. The estimated fracture toughness values obtained from the indentation technique showed good agreement with those from conventional fracture toughness tests based on CTOD. In addition, we confirmed that the proposed model can be also applied in the brittle material through modification of void volume fraction.


1993 ◽  
Vol 2 (1) ◽  
pp. 35-38 ◽  
Author(s):  
G. K. Beshish ◽  
C. W. Florey ◽  
F. J. Worzala ◽  
W. J. Lenling

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