Preferred orientation and interfacial structure in extruded nano-Al3BC/6061 Al

Publication date: 5 October 2017
Source:Materials & Design, Volume 131
Author(s): Yongfeng Zhao, Xia Ma, Houwen Chen, Xiaojun Zhao, Xiangfa Liu
To meet the increasing demand of high strength and lightweight, the novel platelet nano-Al3BC reinforcements with average thickness of 85nm and width of 267nm are in-situ incorporated into the 6061 alloy. The preferred orientation and Al3BC/Al interfacial structure are characterized after extrusion and their relationships with the properties are unveiled in this work. Microstructure characteristics reveal that Al3BC particles distribute in a preferred orientation: {0001}Al3BC//ED (Extrusion Direction), while α-Al also present similar rules: 〈110〉//ND (Normal Direction); <111, ED>=4.5°. The Al3BC/Al interface after extrusion is detected to be semi-coherently bonded with segregation of Fe, Si, Mg elements and the orientation relationship changes to0001Al3BC//31−1Al,112−0Al3BC//011Al, which is divergent from our previous work without extrusion. According to the analysis, the changes are determined by preferred orientation distributions of platelet Al3BC particles and α-Al. Consequently, the preferred orientation and semi-coherent interface collectively contribute to the prominent enhancement of Al3BC particles on matrix alloy at both room and elevated temperatures. The maximum UTS of Al3BC/6061 composites at room temperature, 200°C and 300°C can reach up to 622MPa, 445MPa and 258MPa, respectively.

Graphical abstract

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