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| Investigation on the microstructure and properties of hot extruded graphene/Al matrix composite |
| ZHANG Hui1，4，PEI Dongjie2，NIU Bingbo3 |
| （1.School of Mechanical Engineering, Zhengzhou University of Science & Technology, Zhengzhou 450064, China;
2. School of Mechanical and Engineering, Zhengzhou University, Zhengzhou 450001, China; 3. School of Materi‐
als Science & Engineering, Zhengzhou University, Zhengzhou 450001, China; 4.Zhengzhou Advanced Manufac‐
turing Engineering Research Center of Key Parts for Dental Implant, Zhengzhou 450001, China） |
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Abstract With the continuous development of science and technology, in order to meet the requirements of mili‐
tary, aerospace, automobile and electronic industries for higher performance, function and structure of aluminum al‐
loy, Al matrix composites with high specific strength, high specific stiffness, low density, low thermal expansion
coefficient and high wear resistance have become key new materials in this field because of their excellent mechan‐
ical properties and processability. In this paper, the graphene/Al matrix composites with a mass fraction of GO
being 1% were prepared by the powder metallurgy. The microstructure, mechanical properties and fracture mor‐
phologies of the sintered and extruded composites were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and tensile testing machine. The distribution of gra‐
phene nanosheets in Al-based composites before and after hot-extrusion was systematically studied, and then the in‐
fluence of hot-extrusion process on the structure and properties of graphene/Al-based composites was ascertained.
The results show that the structure of the extruded graphene/Al matrix composite is uniform and dense, and the
number of defects and pores is significantly reduced compared with the sintered state. Ultrasonic dispersion and
hot extrusion process effectively suppressed the harmful interfacial reaction between graphene and Al matrix. The
tensile strength and elongation of the extruded graphene/Al matrix composite is 161.34 MPa and 23.57%, which
were 29.7% and 13.5% higher than those of the sintered state (124.41 MPa, 20.78%), respectively. The fracture
morphology shows that the fracture dimples of the sintered graphene/Al matrix composite are small and shallow,
and the tear edges are bright. However, the dimples of extruded graphene/Al matrix composite are large and deep,
with different sizes, and there are fractured graphene and deep detachment pits at the same time.
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Received: 05 August 2022
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2023, Vol. 33 
