Influence of compaction pressure and Si₃N₄/ZrO₂ reinforcement on the properties of aluminium hybrid composites

ABSTRACT

In the present study, the aluminium hybrid composites (AHCs) are developed by the powder metallurgy method. Pure aluminium is reinforced with varying weight percentages of ceramic reinforcements (Si₃N₄ and ZrO₂). Pure aluminium powder is mixed with 3 wt% Si₃N₄ and (0, 1.5, 3 and 4.5 wt%) ZrO₂ powder in a centrifugal ball mill at a high speed of 600 rpm for 2.5 hours. The XRD results of the AHC powders shows that no interfacial reaction takes place during the ball milling process. The powder composites are then compacted at three different compaction pressure (340,420 and 500MPa) and sintered in a tube furnace at 500 °C for 30 minutes under an Argon environment. The SEM results of different composites show that the reinforcement and matrix particles are distributed uniformly with the accumulation of nano-size ZrO₂ particles. The density and micro-hardness improve with high compaction pressure and weight percentages of the reinforcements but the porosity decreases. The maximum hardness value is found as 72 VHN for sample E (Al+3 wt% Si₃N₄ + 4.5 wt% ZrO₂) at 500 MPa.

KEYWORDS:

• Hybrid composites
• powder metallurgy
• ball milling
• reinforcement
• compaction

Acknowledgments

The authors would like to acknowledge the University Grant Commission to support this work under the Maulana Azad Minority Fellowship program, No- 2017-18/MANF-2017-18-UTT-84333.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the University Grants Commission [2017-18/MANF-2017-18-UTT-84333].