Effect of Sintering Parameters on the Mechanical Properties and Wear Performance of Alumina Inserts

Abstract

The sintering temperature and holding time have a significant impact on the densification of a ceramic compact. In this study, alumina inserts were made with varying sintering temperatures and holding times. The procedure began with the compacting of alumina powders inside a mould with trapezium and round shapes. These inserts were then sintered between 1200 °C and 1400 °C for 5 to 9 h holding time. The sintered samples underwent analysis based on the shrinkage size, density, and microstructure. The sample with the highest density was chosen for additional machining tests. The results showed that the alumina shrinkage ranged from 3 to 6%, with a maximum relative density of 91.3% recorded when the sintering parameter was applied at 1400 °C and a 9 h holding time. The transition of the grain growth was observed depending on the sintering temperature and heating duration. When machined with AISI 1045 carbon steel, the sintered alumina inserts achieved a maximum tool life of 35 s at a cutting speed of 350 m/min. The sintered inserts exhibited brittle characteristics with a dominant notch wear and abrasive mechanisms.

Fabrication, microstructure, and mechanical properties of novel three‐layer structured bionic ceramic cutting tools

“…Subsequently, the grain expansion is triggered, leading to an increase in the contact area of the grain boundaries, in which case the grain interlocking effect happens. The increase in the contact area of the grain boundaries reduces the number of holes, leading to an increase in densification and a decrease in the chance of grain slippage 36 . The presence of distinct cleavage steps in the fracture can be quickly identified as transgranular fracture.…”

“…The increase in the contact area of the grain boundaries reduces the number of holes, leading to an increase in densification and a decrease in the chance of grain slippage. 36 The presence of distinct cleavage steps in the fracture can be quickly identified as transgranular fracture. As a result, the fracture mechanism transforms from intergranular fracture to a mixed mode of transgranular fracture and intergranular fracture with increasing temperature.…”