Study on Preparation and Properties of CNTs/Al2009 Composites by Cryogenic Milling

2020 ◽  
Vol 996 ◽  
pp. 41-47
Author(s):  
Xiao Lei He ◽  
Tian Bing He ◽  
Peng Jun Tang ◽  
Xing Yuan Wang

The CNTs/Al2009 composite powders were prepared by cryogenic milling. The CNTs were uniformly dispersed on the surface of Al2009 powders. And then the CNTs/2009Al composites were fabricated by hot extrusion/hot isostatic pressing method. The effects of CNTs content and cryogenic milling process on the dispersion of CNTs in Al2009 matrix, the microstructure of powders and the properties of composites were studied by Scanning electron microscopy, Raman spectroscopy and tensile strength testing at room temperature. The results showed that the dispersion of CNTs was improved with the extension of ball milling time (1h~4h), but the damage degree of CNTs was intensified. In comparison, CNTs had the highest damage rate at the beginning of ball milling. As the milling time increased, the mechanical properties began to increase slightly and then decreased. When the ball milling time was 2h, the mechanical properties reached the highest. Cryogenic milling could achieve good dispersion in the Al2009 matrix for mixed powders with low CNTs content. When the CNTs content increased to 1.0%, a small amount of agglomeration appeared, but for composites, the strengthening effect of CNTs was more dominant. When CNTs were further added, the dispersion was remarkably lowered and the performance was deteriorated. CNTs (1.0wt.%)/Al2009 composites had excellent mechanical properties. The tensile strength reached 560MPa, which was 25% higher than Al2009.

2021 ◽  
Author(s):  
Hossein Ahmadian

Abstract The effects of multi-walled carbon nano-tubes (MWCNTs) and the ball milling parameters on the mechanical properties of the Al-Mg alloy powders were investigated. Three different composite powders were synthesized through ball-milling process at different time and milling rates. The microstructural and phase analyses were carried out via scanning electron microscopy and X-ray diffraction spectroscopy, respectively. The results indicated that increasing the ball-milling time and rate would lead to the formation of finer particles, which consequently intensifies the plastic deformation and then, results in lower crystallite size. The morphological investigations indicated that while the MWCNTs agglomerates in lower milling rates, increased milling rate not only improve the distribution of the MWCNTs, but also decreases the length of the nano-tubes and promotes their diffusion into Al-Mg matrix. The formation of Al-Mg intermetallic phases through the ball-milling process of the composite powders was also confirmed via microstructural investigations.


2015 ◽  
Vol 830-831 ◽  
pp. 429-432 ◽  
Author(s):  
Udaya ◽  
Peter Fernandes

The paper illustrates Carbon nanotubes reinforced pure Al (CNT/Al) composites and fly ash reinforced pure Al (FA/Al) composites produced by ball-milling and sintering. Microstructures of the fabricated composite were examined and the mechanical properties of the composites were tested and analysed. It was indicated that the CNTs and fly ash were uniformly dispersed into the Al matrix as ball-milling time increased with increase in hardness.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1926 ◽  
Author(s):  
Lei Zhang ◽  
Zhifu Huang ◽  
Yangzhen Liu ◽  
Yupeng Shen ◽  
Kemin Li ◽  
...  

Mo2NiB2-Ni cermets have been extensively investigated due to their outstanding properties. However, studies have not systematically examined the effect of the powder milling process on the cermets. In this study, Mo, Ni, and B raw powders were subjected to mechanical ball milling from 1 h to 15 h. XRD patterns of the milled powders confirmed that a new phase was not observed at milling times of 1 h to 15 h. With the increase in the mechanical ball milling time from 1 h to 11 h, raw powders were crushed to small fragments, in addition to a more uniform distribution, and with the increase in the mechanical ball milling time to greater than 11 h, milled powders changed slightly. Mo2NiB2-Ni cermets were fabricated by reaction boronizing sintering using the milled powders at different ball milling times. The milling time significantly affected the microstructure and mechanical properties of Mo2NiB2-Ni cermets. Moreover, the Mo2NiB2 cermet powder subjected to a milling time of 11 h exhibited the finest crystal size and the maximum volume fraction of the Mo2NiB2 hard phase. Furthermore, the cermets with a milling time of 11 h exhibited a maximum hardness and bending strength of 87.6 HRA and 1367.3 MPa, respectively.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3483
Author(s):  
Shu Mei Lou ◽  
Chuan Dong Qu ◽  
Guang Xin Guo ◽  
Ling Wei Ran ◽  
Yong Qiang Liu ◽  
...  

Aluminum composites reinforced by graphene nanoplates(GNP) with a mass fraction of 0.5% (0.5 wt.% GNP/Al) were fabricated using cold pressing and hot pressing. An orthogonal test was used to optimize the fabrication parameters. Ball milling time, ball milling speed, and ultrasonic time have the largest influence on the uniformity of the graphene in the composites. Afterwards, the microstructure, interfacial properties, and fracture morphology of the composites obtained with different parameters were further analyzed. The results show that ball milling time and ball milling speed have obvious influences on the mechanical properties of the composite. In this paper, when the ball milling speed is 300 r/min and the ball milling time is 6 h, the dispersion uniformity of graphene in the 0.5 wt.% GNP/Al composite is the best, the agglomeration is the lowest, and the mechanical properties of the composites are the best, among which the tensile strength is 156.8 MPa, 56.6% higher than that of pure aluminum fabricated by the same process (100.1 MPa), and the elongation is 19.9%, 39.8% lower than that of pure aluminum (33.1%).


2013 ◽  
Vol 589-590 ◽  
pp. 584-589
Author(s):  
Hui Jun Zhou ◽  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Han Lian Liu ◽  
Hong Tao Zhu ◽  
...  

In this study, titanium carbonitride (Ti(C,N)) based cermets were prepared by submicron particles, sintered in a vacuum and hot-pressing furnace. And the effect of different ball-milling time (36 h, 48 h, 60 h and 72 h, respectively, mostly aimed for mixing) on the mechanical properties of Ti(C,N)-based cermets, including transverse rupture strength (TRS), Vickers hardness (HV20), fracture toughness (KIC) and microstructure were investigated. The results showed that the TRS, hardness and fracture toughness were all improved with an increase in ball-milling time (not more than 60 h). Scanning electron microscopy (SEM) investigations on the microstructure of cermets with different ball-milling time revealed that the compound powders were not very well-distributed as a whole and there were coarse hard phase grains, but the microstructure was very homogeneous in parts, and the microstructure of cermets with a ball-milling time of 60 h is relatively more homogeneous. So a refinement to Ti(C,N) raw particles is needed in later studies.


2013 ◽  
Vol 669 ◽  
pp. 149-153
Author(s):  
Xiao Lan Cai ◽  
Zheng Li ◽  
Qing Jun Wang

High energy ball milling was used to preparation SiC/Al composites flakes. The research found the milling parameter of high energy milling was the ball/powder ration is 20:1, the rotary speed is 800 r/min, the milling time is 100min.Also researched the molding process of SiC/Al composites, the change of grain size and the weight fraction of the SiC, The research also found the mechanical properties of SiC/Al composites affected by the molding process. It was found that to reduce particle size and increasing of weight fraction of SiC, tensile strength of the SiC/Al composites increased. When the weight fraction of SiC in the SiC/Al composites is about 16%, the mechanical properties of SiC/Al composites about the hardness and tensile strength also get the high-point, the hardness and tensile strength is about 95HB and 248MPa.


2009 ◽  
Vol 60-61 ◽  
pp. 155-159 ◽  
Author(s):  
Hong Yu Wang ◽  
Dun Wen Zuo ◽  
Shou Xin Yu ◽  
Dan Zhang

The compound of micron powders and nanometer powders is a magnificent step in the application and development of metal matrix composite reinforced by nanometer particles. By taking nano-Al2O3 powders and Ni-based micron powders as the research object, the preparation process of metal matrix micro/nano-powders reinforced by nanometer particles with high energy ball-milling is discussed from three aspects: the additive process of nanometer powders, the additive content of nanometer powders, and the required ball-milling time in the paper. The results show that the additive process of nanometer powders which uses directly the dispersed uniformly nanometer suspensions as grinding medium can effectively decrease and avoid nanometer powders’ agglomeration of composite powders. Nanometer particles are well distributed in the composite powders. The optimum additive content of nanometer powders is consistent with the theoretical model of mixture ratio, which is determined by the ratio of the average diameter of micron powders and nanometer powders and their density of corresponding solid materials. Meanwhile, the required ball-milling time for preparation of better uniformity composite powders is no more than 0.5hr. This implies that the preparation process has a high productivity. Moreover, the preparation process is verified through other nanometer powders including nano-SiC powders and nano-CeO2 powders.


2007 ◽  
Vol 353-358 ◽  
pp. 429-432 ◽  
Author(s):  
Jin Yi Wu ◽  
Ke Chai

Ti2SnC dispersion-strengthened (DS) copper matrix composites were prepared by hot-pressing method. The changes of mechanical properties of the composites as a function of microstructure were studied. The results demonstrated that the grain size of Cu decreased pronouncedly by incorporating of Ti2SnC, and the strengthening effect was significant. The addition of 5 vol.% Ti2SnC particles to Cu resulted in a near five-fold increase in the yield strength and the tensile strength also increased by 188 MPa. The magnitude of the increase was a function of the change of the microstructure.


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