scholarly journals Preparation and elastic–plastic indentation response of MgAlON transparent ceramics

Author(s):  
Wei Zhang ◽  
Yuezhong Wang ◽  
Jian Chen ◽  
Ruomei Jiang ◽  
Zitao Shi ◽  
...  
1998 ◽  
Vol 13 (9) ◽  
pp. 2662-2671 ◽  
Author(s):  
A. Newman ◽  
T. Jewett ◽  
S. Sampath ◽  
C. Berndt ◽  
H. Herman

The influence of microstructure on the indentation cracking behavior of molybdenum disilicide (MoSi2) has been examined. The indentation response of samples produced by various methods has been measured to examine the elastic/plastic nature, hardness, and fracture toughness. Fracture toughness comparisons were made by measuring indentation crack lengths, observing the elastic/plastic indentation response, and quantifying the differences in the indentation cracking behavior. Further information was gained by monitoring the acoustic activity during indentation for selected specimens. It has been observed that the fine grain size and the dispersion of the silica phase promote microcracking and crack deflection.


2018 ◽  
Vol 931 ◽  
pp. 84-90 ◽  
Author(s):  
Aleksey N. Beskopylny ◽  
Andrey A. Veremeenko ◽  
Elena E. Kadomtseva ◽  
Natalia I. Beskopylnaia

In the practice of civil engineering, the methods of impact diagnostics of materials find their application, allowing quickly and accurately measure the required strength characteristics at any point in the structure. Impact methods offer many advantages, for example, at smaller dimensions can be developed big the contact force, it can be recorded more information about the response of the material to dynamic impact and others. This approach is widely used in determining the hardness of materials and makes it possible to determine the complex mechanical characteristics: yield strength, ultimate strength, and elongation. In the paper we consider the axisymmetric problem of the impact of the conical indenter on the plate, laying on Winkler Foundation under elastic-plastic deformation. The solution is based on the phenomenological model of elastic-plastic indentation in a quasistatic formulation. The general deformations of the plate are considered elastic, and the local, in the contact zone, are elastoplastic. The main characteristics of the impact are determined: the force of the contact interaction, the local indentation, the contact time. The device and methods of determining the strength characteristics of plates under specified conditions of impact were developed on the basis of obtained solutions. The proposed method has been tested on many building structures: bridges, trusses, structural structures of artificial structures, reinforcement bars, welded joints.


1993 ◽  
Vol 8 (6) ◽  
pp. 1291-1299 ◽  
Author(s):  
S. Harvey ◽  
H. Huang ◽  
S. Venkataraman ◽  
W.W. Gerberich

Atomic force microscope measurements of elastic-plastic indentation into an Fe−3 wt. % Si single crystal showed that the volume displaced to the surface is nearly equal to the volume of the cavity. The surface displacement profiles and plastic zone size caused by a 69 nm penetration of a Vickers diamond tip are reasonably represented by an elastic-plastic continuum model. Invoking conservation of volume, estimates of the number of dislocations emanating from the free surface are reasonably consistent with the number of dislocations that have formed in the plastic zone to represent an average calculated plastic strain of 0.044.


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