Microstructures and Dynamic Compression Properties of a High Reinforcement Content TiB2/Al Composite

2007 ◽  
Vol 546-549 ◽  
pp. 639-642
Author(s):  
De Zhi Zhu ◽  
Gao Hui Wu ◽  
Long Tao Jiang ◽  
Guo Qin Chen

A high reinforcement content TiB2/2024Al composite with an average particle size of 8μm was fabricated by squeeze casting technology. The dynamic compression behaviors of the composite under varied strain rates were measured using split Hopkinson pressure bar, and its microstructure and fracture characteristic were examined. Resluts revealed that the composite was dense and homogenerous, and the TiB2-Al interface was clean without interfacial reactants. At high strain rate, the TiB2/Al composite showed insensitive to the strain rate, and both the flow stress and the elastic modulus improved little with an increase of the strain rate. The composite failed macroscopically in shear fracture and in split, which were caused by cracking of large reinforcement particles and interface failures under dynamic load.

2016 ◽  
Vol 879 ◽  
pp. 1159-1163 ◽  
Author(s):  
Rui Liu ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rong Chen ◽  
Yang Yu ◽  
...  

This paper aimed to study the quasi-static and dynamic properties of a titanium alloy plate with nominal composition Ti-3.5Al-2.5V-1.5Fe-0.25O (ATI 425TM titanium alloy with lower limit of Al element) in thickness of 8 mm. The quasi-static tensile properties were investigated by MTSTM testing system at strain rate of 10-3 s-1, while dynamic compression properties by Split Hopkinson Pressure Bar system at strain rate of 3000±200 s-1. The results show that the quasi-static prperties of the Ti-3.5Al-2.5V-1.5Fe-0.25O plate are comparable to the commercial Ti-6Al-4V plate in 8mm-thick. The Ti-3.5Al-2.5V-1.5Fe-0.25O plate exhibats good dynamic strength. The average dynamic flow stress is 100MPa higher than that of Ti-6Al-4V plate. However, the maximum strain during homogeneous plastic deformation of Ti-3.5Al-2.5V-1.5Fe-0.25O plate is only 50~60% of that of Ti-6Al-4V plate.


2018 ◽  
Vol 183 ◽  
pp. 02012
Author(s):  
Miloslav Popovič ◽  
Jaroslav Buchar ◽  
Martina Drdlová

The results of dynamic compression and tensile-splitting tests of concrete reinforced by randomly distributed short non – metallic fibres are presented. A Split Hopkinson Pressure Bar combined with a high-speed photographic system, was used to conduct dynamic Brazilian tests. Quasi static test show that the reinforcement of concrete by the non-metallic fibres leads to the improvement of mechanical properties at quasi static loading. This phenomenon was not observed at the high strain rate loading .Some explanation of this result is briefly outlined.


2011 ◽  
Vol 704-705 ◽  
pp. 935-940
Author(s):  
De Zhi Zhu ◽  
Wei Ping Chen ◽  
Yuan Yuan Li

Strain-rate sensitivities of 55-65vol.% aluminum 2024-T6/TiB2composites and the corresponding aluminum 2024-T6 matrix were investigated using split Hopkinson pressure bar. Results showed that 55-65vol.% aluminum 2024-T6/TiB2composites exhibited significant strain-rate sensitivities, which were three times higher than that of the aluminum 2024-T6 matrix. The strain-rate sensitivity of the aluminum 2024-T6 matrix composites rose obviously with reinforcement content increasing (up to 60%), which agreed with the previous researches. The aluminum 2024-T6/TiB2composites showed hybrid fracture characteristics including particle cracking and aluminum alloy softening under dynamic loading. The flow stresses predicted by Johnson-Cook model increased slowly when the reinforcement volume fraction ranged in 10%-40%. While the reinforcement volume fraction was over 40%, the flow stresses of aluminum matrix composites increased obviously and the strains dropped sharply. Keywords: Composite materials; Dynamic compression; Stress-strain relationship


2017 ◽  
Vol 898 ◽  
pp. 199-203 ◽  
Author(s):  
Rui Liu ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Yang Yu ◽  
Xiao Yun Song

This paper aimed to study the dynamic compression properties of Ti-6Al-4V titanium alloy sections. The Ti-6Al-4V sections were extruded above the β-transus temperature with extruding ratio of 85, and then heat treated by conventional annealing at 750°C, or annealing at 1200°C by two routes. Dynamic compression properties were investigated by Split Hopkinson Pressure Bar system at strain rate of 3000±200 s-1. The results show that the dynamic compression properties of as-extruded specimens are comparable to the specimens after conventional annealing at 750°C. Compared to Widmannstatten microstructure with original beta grains in size of 200 μm ~ 300 μm obtained by conventional annealing, the microstructure obtained by annealing at 1200°C with coarse grains consisted of fine α-lamellae exhibits comparable dynamic strength but the capability of plastic deformation reduced about 20%. For the microstructure obtained by annealing at 1200°C with coarse grains consisted of coarse α-lamellae, the dynamic strength slightly decreased, while the capability of plastic deformation reduced about 60%.


2020 ◽  
Vol 999 ◽  
pp. 83-90
Author(s):  
Xiao Ju Gao ◽  
Hasigaowa ◽  
Meng Yong Sun ◽  
Cheng Dong Liao ◽  
Wei Ping Huang ◽  
...  

SiC/B4C composite was obtained using the reaction sintering method with Si infiltration, which exhibited excellent mechanical properties. The dynamic compressive response was investigated using a Split Hopkinson pressure bar at high strain rates ranging from 0.4×103 to 1.2×103 s-1. The results show that the dynamic strength of the SiC/B4C composite obtains a peak value at a strain rate of 1000/s, while its strain increased continuously with increasing strain rate. The dynamic loading mode of SiC/B4C composite exhibited three deformation regions, including an inelastic deformation region, rapid loading region and failure region. The dynamic failure mode of SiC/B4C composite depended upon the strain rate.


2014 ◽  
Vol 584-586 ◽  
pp. 1089-1096
Author(s):  
Remdane Boutemeur ◽  
Mustapha Demidem ◽  
Abderrahim Bali ◽  
El Hadi Benyoussef

The aim of this study is to present a model for assessing the dynamic compression behaviour of a micro-concrete. This model is based on the results of numerous tests providing the developments of the mechanical characteristics of the material on a wide range of strain rate from 10-4s-1to 10+3s-1.The Split Hopkinson Pressure Bar (SHPB) dispositive, based on the wave propagation theory in materials, has-been adopted to carry out the dynamic tests on the investigated material. The proposed model is composed of two terms, each characterizing the different contributions noted in the two major explored areas of strain rate.


2009 ◽  
Vol 631-632 ◽  
pp. 513-518 ◽  
Author(s):  
Dong Feng Cao ◽  
Li Sheng Liu ◽  
Hai Mei ◽  
Qing Jie Zhang

In this paper the sensitivity of strain rate and size effect with different particle volume fraction in SiCp/Al Composite were studied through the experiment. Specimens with 40% and 30% SiC particle volume fraction were made. There are three types of particle sizes in each volume fraction. The sensitivity of strain rate and the effect of particle size in Al matrix composites reinforced with the different volume fraction were investigated, using the split Hopkinson pressure bar and Instron5882 universal material testing machine. The surface microstructure of the specimens in each composite was examined using optical microscopy and SEM. Through the strain-stress curves, the sensitivity of strain rate can be obtained. The experimental results show that the sensitivity of strain rate increases with the increasing of particle volume fraction. At the same volume fraction, the size effect were observed obviously and higher flow stresses were obtained in the composites reinforced with small particles than that in the composite with large particles.


2014 ◽  
Vol 1015 ◽  
pp. 328-331 ◽  
Author(s):  
Rui Liu ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Yang Yu ◽  
Yan Yan Fu ◽  
...  

Ti-6Al-4V plates in thickness of 8 mm were directly hot rolled and then heat treated in various routes by a single electron beam cold hearth melted (EBCHM) ingot, in which the weight percentage of recycled titanium scraps was at least about 50 wt%. The dynamic stress-strain behaviors of the plates with typical microstructures were investigated by Split Hopkinson Pressure Bar system at the strain rates of 2000 s-1~ 3000 s-1. The results show that the dynamic compression properties of EBCHM-ingot Ti-6Al-4V plates are relative to that of commercial VAR-ingot plates. The dynamic properties in normal direction of the plates are not sensitive to variations in the fraction of primary alpha phase.


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