Effect of Preparation Parameter on Microstructure and Grain Refining Behavior of In Situ AlN-TiN-TiB2/Al Composite Inoculants on Pure Aluminum

Abstract

Abstract:The formation of in situ AlN-TiN-TiB 2 /Al composite inoculants, which contain multi-phase refiner particles including AlN, TiN, TiB 2 , Al 3 Ti, and α-Al, was investigated using nitrogen gas injection. The effects of the main preparation parameters such as nitriding temperature, nitriding time, Ti content in melts, on the microstructure and grain refinement of in situ AlN-TiN-TiB 2 /Al composite inoculants were studied. The shape, content and size of different ceramic particles in the inoculants can be tuned by controlling the nitriding temperature and time, inducing excellent refining and reinforcing effects on pure aluminum. As a result, the average grain size of pure aluminum can be reduced to about 122 ± 22 µm from original 1010 ± 80 µm by adding 0.3 wt % inoculants. The mechanical properties including the tensile strength, yield strength and microhardness of the refined as-cast pure aluminum are also improved.

Evaluation of Pure Aluminium Inoculated with Varying Grain Sizes of an Agro-waste based Inoculant

“…Addition of some special master alloys that have much particles functioning as the substrates for heterogeneous nucleation can cause the grain size of the inoculated alloys to be noticeably reduced and enhance the comprehensive properties [10 -12]. In reality, majority of the master alloys are linked to Al-based composites, in which the aluminium-based solid solution is the matrix and the inoculant particle is the secondary phase [9].…”

“…Common aluminium melt treatment inoculants in use include MgFeSi [7], Al-Ti-C and Al-3Ti-1B [8], in situ AlN-TiN-TiB2/Al composite inoculants [9]. Addition of some special master alloys that have much particles functioning as the substrates for heterogeneous nucleation can cause the grain size of the inoculated alloys to be noticeably reduced and enhance the comprehensive properties [10 -12].…”