Effect of Graphite Flake Size on the Strength and Thermal Conductivity of Graphite Flakes/Al Composites

doi:10.11900/0412.1961.2017.00015

IMR OpenIR

	Effect of Graphite Flake Size on the Strength and Thermal Conductivity of Graphite Flakes/Al Composites
	Liu Xiaoyun 1,2; Wang Wenguang 2; Wang Dong 2; Xiao Bolv 2; Ni Dingrui 2; Chen Liqing 1; Ma Zongyi 2
通讯作者	Ma Zongyi(zyma@imr.ac.cn)
	2017-07-01
发表期刊	ACTA METALLURGICA SINICA
ISSN	0412-1961
卷号	53 期号:7 页码:869-878
摘要	Graphite flakes reinforced Al matrix composites (G(f)/Al) with low density, good machining property and high thermal conductivity are considered an excellent heat sink materials used in electronic industry. When the composites are manufactured by liquid method such as liquid infiltration, it is easy to achieve a high thermal conductivity composite. However, the Al4C3 phase would be formed in the composite, which will decrease the corrosion properties of the composites. The powder metallurgy technique could avoid the formation of the Al4C3 phase. In this work, three seized graphite flakes (150, 300, 500 mu m) were used to investigate the effect of the graphite flake size on the strength and thermal conductivity of G(f)/Al alloy composites. The 50% G(f)/Al alloy (volume fraction) composites were fabricated by the powder metallurgy technique. The density of all the three Gf/Al alloy composites were similar to the theoretical density. The graphite flakes had a well bonding with Al alloy matrix without cracks and pores. The (001) G(f) basal plane of the graphite flakes were almost parallel to the circular plane (xy plane) of the composites ingot. However, for the small graphite flakes, their (001) G(f) basal plane was not well parallel to the xy plane of the composite ingot due to the powder metallurgy process. For the large graphite flakes, they exhibited a good orientation in the xy plane of the composite ingot. The strength of the G(f)/Al alloy composites decreased with the increase of the graphite flake size. For the 150 mm graphite flake, the bending strength of the Gf /Al alloy composite was 82 MPa. However, for the 500 mm graphite flake, the bending strength of the composite decreased to 39 MPa. Due to the low strength between the layers of the graphite flake, the cracks were prone to expand in the graphite flake. As the size of the graphite flake increased, this phenomenon became more obviously. It is easy to observe that the graphite flakes peeled off on the fracture surfaces. When the size of the graphite flake increased from 150 mm to 500 mm, the thermal conductivity increased by 63%. The highest thermal conductivity was 604 W/(m . K). The interfacial thermal conductance (h(c)) of the composites were calculated by the Maxwell-Garnett type effective medium approximation model. The hc of 300 and 500 mm graphite flake G(f)/Al alloy composites were slightly lower than the theoretical value (calculated by the acoustic mismatch model). However, the hc of the 150 mm graphite flake G(f) /Al alloy composite was lower than that of the theoretical value. Besides the size of the graphite flakes, the shape, distribution and defect of the graphite flakes also influenced the thermal conductivity of the composites.
关键词	graphite flake aluminum matrix composite thermal conductivity mechanical property
资助者	National Natural Science Foundation of China
DOI	10.11900/0412.1961.2017.00015
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[U1508216] ; National Natural Science Foundation of China[51271051]
WOS研究方向	Metallurgy & Metallurgical Engineering
WOS类目	Metallurgy & Metallurgical Engineering
WOS记录号	WOS:000408285400012
出版者	SCIENCE PRESS
引用统计	被引频次：8[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/125014
专题	中国科学院金属研究所
通讯作者	Ma Zongyi
作者单位	1.Northeastern Univ, State Key Lab Rolling & Automat, Shenyang 110016, Liaoning, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Liu Xiaoyun,Wang Wenguang,Wang Dong,et al. Effect of Graphite Flake Size on the Strength and Thermal Conductivity of Graphite Flakes/Al Composites[J]. ACTA METALLURGICA SINICA,2017,53(7):869-878.
APA	Liu Xiaoyun.,Wang Wenguang.,Wang Dong.,Xiao Bolv.,Ni Dingrui.,...&Ma Zongyi.(2017).Effect of Graphite Flake Size on the Strength and Thermal Conductivity of Graphite Flakes/Al Composites.ACTA METALLURGICA SINICA,53(7),869-878.
MLA	Liu Xiaoyun,et al."Effect of Graphite Flake Size on the Strength and Thermal Conductivity of Graphite Flakes/Al Composites".ACTA METALLURGICA SINICA 53.7(2017):869-878.