Measurement of High Strain Rate Indentation-Induced Deformations in Al2O3/SiCp Composite Ceramics

2020 ◽  
Vol 1001 ◽  
pp. 35-40
Author(s):  
Yuan Fei Gao ◽  
Zhao Xia Si ◽  
Xiao Yan Wang ◽  
Meng Yu Zhao

Al2O3/SiCp composite ceramics with 2 vol%, 5 vol% and 10 vol% SiC nanoparticles additions were hot pressed at 1650 °C. The polished ceramic discs were prepared and indented at high strain rate using a compressed gas gun with tiny tungsten carbide bullets. The microstructure and mechanical properties were obtained to explain the dynamic deformation behavior of Al2O3/SiCp ceramics. Cr3+ fluorescence mapping was used to examine the residual stress and plastic deformation induced on the surface of each target. The residual compressive stress area around the crater was evenly distributed, while the greatest plastic deformation was found at the hitting point of the bullet tip. It can be calculated that the high temperature of 1400K may be produced at the instant of the bullet impact and result in large plastic deformation region and low residual stress of the Al2O3/SiCp ceramic.

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1145
Author(s):  
Jincheng Nie ◽  
Shengci Li ◽  
Huilong Zhong ◽  
Changjing Hu ◽  
Xiangsong Lin ◽  
...  

Laser welding is widely used for the joining of aluminum alloy in the automotive industry, and the vehicles produced are inevitably subjected to high strain rate loading during their service. Therefore, this paper studied the mechanical properties of 6061-T6 aluminum alloy and its laser welded joint at strain rates between 0.0003 and 1000 s−1. Results showed that the microstructure of welded material (WM) was much finer than base material (BM), typical columnar crystals grew perpendicularly to the fusion line, and the minimum hardness value (~56 HV) was obtained inside WM. The strength and dynamic factors of BM and WM increased with increasing strain rate, and the strength of WM was less sensitive to strain rate compared with BM. The strain rate effect was not homogenous in the plastic deformation region. The modified Johnson–Cook (J–C) model which introduced the term C = C1 + C2·ε could well describe the dynamic plastic deformation of BM. However, the fitted results of the simplified J–C model were overall better than the modified J–C model for WM, especially for high strain rate (1000 s−1). These findings will benefit the determination of the dynamic deformation behavior of laser welded aluminum alloy under high strain rates, and could provide a better understanding of lightweight and the safety of vehicles.


2014 ◽  
Vol 8 (2) ◽  
Author(s):  
Ehsan Etemadi ◽  
Jamal Zamani ◽  
Alessandro Francesconi ◽  
Mohammad V. Mousavi ◽  
Cinzia Giacomuzzo

2003 ◽  
Vol 341 (1-2) ◽  
pp. 273-281 ◽  
Author(s):  
Kyung-Tae Park ◽  
Duck-Young Hwang ◽  
Young-Kook Lee ◽  
Young-Kuk Kim ◽  
Dong Hyuk Shin

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Prasanta K. Das ◽  
Vishal Kumar ◽  
Prasenjit Khanikar

Abstract High entropy alloys (HEAs) are primarily known for their high strength and high thermal stability. These alloys have recently been studied for high strain rate applications as well. HEAs have been observed to exhibit different properties when subjected to different strain rates. Very few published results on HEAs are available for high strain rate loading conditions. In addition, modeling and simulation work of microstructural details, such as grain boundary and precipitates of HEAs have not yet been investigated. However, at an atomistic length scale, molecular dynamics simulation works of HEAs have already been published. In this study, a detailed microstructural analysis of plastic deformation of the material under high strain rate loading has been performed using dislocation density based crystal plasticity finite element modeling. The primary objective is, therefore, to assess the strengthening effects due to precipitates on a particular high entropy alloy Al0.3CoCrFeNi with ultrafine grains having randomly distributed NiAl precipitates.


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