Nanoindentation, Compressive and Tensile Deformation Study of In-Situ Al–AlN Metal Matrix Composites

Abstract

In-situ formation of ceramic particulate as a reinforcement in Al matrix results in superior mechanical properties of synthesized Al based composites. Resulting composites are thermodynamically stable with clean particulates having strong bonding with matrix. In the present study, Al melt held at 700°C is nitrogenated using NH 4 Cl ? CaO as a nitriding precursor to form ultrafine AlN particulates in melt. Nanoindentation, tensile and compressive tests are conducted on the synthesized composite to evaluate its deformation behavior. The load bearing capacity of ultrafine sized, well bonded in-situ AlN particulate with Al matrix show a prominent improvement in nanoindentation hardness, compressive, and tensile strength of composites. In comparison to monolithic Al, composites reveal increase in yield strength to an extent of 60-96 % and 88-100 % under compressive and tensile loads respectively. Nanoindentation results of the composites also exhibit higher hardness and modulus of elasticity in range of 11-16 % and 16-34 % respectively in comparison to pure Al matrix.

Atomic Ordering at the Interfaces Between Liquid Aluminum and Polar AlN{0 0 0 1} Substrates

“…The experiments have found that the prepared AlN/Al composites containing well distributed AlN nano-partciles produced by means of nitriding of Al-liquids exhibit improved mechanical performances. [2,[19][20][21] This topic deserves further investigation.…”

“…The obtained information is helpful to understand the interaction between liquid Al to AlN particles, and further to enrich our understanding of heterogeneous nucleation, [5,6,16,52,53] as well as for AlN-containing composites [2,[19][20][21][22] and ceramic-metal welding. [27] V. CONCLUSIONS…”

“…The obtained information here is helpful to get insight into not only the role of AlN particles in heterogeneous nucleation of Al-based metals/alloys, further into designing of new grain refiners, but also the chemistry of AlN-containing nano-composites. [18][19][20][21][22][27][28][29]…”