Effect of Ultrasonic Treatment on Microstructure and Property of SiC Particles Reinforced Aluminum Matrix Composites

2020 ◽  
Vol 07 (03) ◽  
pp. 175-184
Author(s):  
翔 贾
2016 ◽  
Vol 256 ◽  
pp. 81-87 ◽  
Author(s):  
Ju Fu Jiang ◽  
Ying Wang ◽  
Shou Jing Luo

Semisolid slurries of 7075 aluminum matrix composite reinforced with nano-sized SiC particles were fabricated by ultrasonic assisted semisolid stirring (UASS) method. Rheoforming and thixoforming of typical cylindrical parts were investigated. The results show that high-quality semisolid slurries with spheroidal solid grain of 38 µm were fabricated by UASS. The nano-sized SiC particles were dispersed uniformly due to transient cavitation and acoustic streaming of ultrasonic wave and high and controllable viscosity of semisolid slurry. Typical cylindrical composite parts with good surface quality and complete filling were rheoformed and thixoformed successfully. Ultimate tensile strength (UTS) of the rheoformed and thixoformed composite parts are enhanced due to addition of nano-sized SiC particles. However, elongation decreased as compared to those of the matrix parts. Maximum UTS of 550 MPa was achieved in the thixoformed composite part with T6 treatment. Increase of dislocation density around the reinforcement particles leads to improvement of the strength and wear resistance of the composite.


2007 ◽  
Vol 546-549 ◽  
pp. 657-660
Author(s):  
Ming Hu ◽  
Hai Ting Hu ◽  
Zheng Xiao Hong ◽  
Suk Bong Kang ◽  
Kwang Jun Euh

The microstructures of sprayed SiCp/Al composite fabricated by thermal spraying technique by optical microscope (OM)scanning electronic microscope (SEM), transmission electronic microscope (TEM), X-ray (diffractometer) XRD, selected area electron diffraction (SAED), energy dispersive spectrum (EDS) techniques, were investigated. The composite consisted of SiC and Al, along with single crystal Si and amorphorous Si, and tiny Al2O3. The interfaces between SiC particles and Al matrix bonded well, and tiny reactants like Al2O3 were found near the interfaces. The mechanisms of chemical reactions during sprayin were discussed g. The nano-Al grains and particles were observed in the sprayed composite. The formation of nano-Al grains and particles of SiCp/ Al composites were explained. It has been found that Several interface relationships existed in the sprayed composite.


2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540002 ◽  
Author(s):  
Dongfeng Cheng ◽  
Jitai Niu ◽  
Zeng Gao ◽  
Peng Wang

This experiment chooses A356 aluminum matrix composites containing 55% SiC particle reinforcing phase as the parent metal and Al – Si – Cu – Zn – Ni alloy metal as the filler metal. The brazing process is carried out in vacuum brazing furnace at the temperature of 550°C and 560°C for 3 min, respectively. The interfacial microstructures and fracture surfaces are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy spectrum analysis (EDS). The result shows that adequacy of element diffusion are superior when brazing at 560°C, because of higher activity and liquidity. Dislocations and twins are observed at the interface between filler and composite due to the different expansion coefficient of the aluminum alloy matrix and SiC particles. The fracture analysis shows that the brittle fracture mainly located at interface of filler and composites.


Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Ainhoa Riquelme ◽  
Pilar Rodrigo ◽  
María Dolores Escalera-Rodriguez ◽  
Joaquin Rams

Ceramic-reinforced metal matrix composites are known for their high wear resistance. A coating based on these materials would be helpful to improve the wear behavior of aluminum alloys. Laser cladding has been used to deposit a coating consisting of an aluminum alloy reinforced with SiC particles on an AA6082 aluminum alloy. Laser cladding is a very energetic technique that causes the SiC particles to react with the molten aluminum to form Al4C3, which degrades the particles and reduces the properties of the coating. The formation of this detrimental compound was successfully achieved with the addition of Silicon and Titanium to the composite matrix. The microstructures of the newly developed material were characterized and the wear behavior was studied under dry sliding conditions on a pin-on-disc tribometer. The relationship between the microstructure and wear behavior was identified. The absence of Al4C3 in the Al40Si/SiC and Al12Si20Ti/SiC coatings’ microstructures resulted in an abrasion mechanism instead of a delamination mechanism. The wear behavior changed along the sliding distances. During the first 200 m of sliding distances, the wear rate of all coatings was lower than the uncoated one due to their higher microhardness. For longer sliding distances, the wear resistance of the uncoated AA6082 was higher than the coated ones due to the formation of a lubricant oxide layer on the AA6082 worn surface. For 1000 m of wear distances, the wear behavior was different for each coating. The wear rate of the Al12Si/SiC coating continued growing due to the delamination mechanism and the presence of Al4C3 that acted as starting crack points. The wear rate of the Al40Si/SiC coating decreased due to the formation of a thin, superficial oxide layer. The wear rate of the Al12SiTi/SiC progressively decreased along the sliding distance to below the substrate wear rate.


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