Effects of Process Control Agent on the Synthesis of AlN-Carbon Nanotube by Ball-Milling

Abstract

Aluminum and its alloy are of importance due to high specific strength. In particular, aluminum matrix composites have good corrosion resistance and mechanical property at high temperatures. However, enhanced mechanical strength and wear resistance via proper heat treatments are strongly required for many structural applications. For this purpose, we synthesized carbon nanotube (CNT)-reinforced aluminum matrix composites by employing a new method. We employed controlled ball-milling and sintering: the use of some specific process control agents (PCAs) for ball-milling and sintering in a specific atmosphere. The use of our PCAs was beneficial both for homogeneous mixing and for the formation of hard dispersoids. Hardened layers was formed at the surface of the present aluminum-CNT composites as a result of reaction of aluminum with PCAs and nitrogen in the processing atmosphere. The resulting materials after sintering showed interesting mechanical properties, combined with surface hardening. The hardening mainly stems from the formation of Al-N-O phase at the surface of specimens.

Fabrication of Al2O3/AlN micro-composites designed for tailored physical properties

“…Interdiffusion differences were also evident in the XRD patterns (Figure 3(c)). Although the Al 3 O 3 N secondary phase was found in specimens sintered at 1600℃ for 0 min, it was not detected in specimens sintered under the other conditions [22,23]. Therefore, the optimized sintering …”

Microstructure and Damping Capacity of AlN_p/Mg-Al Composites with Different Particle Contents

“…Additionally, its thermal expansion coefficient is lower than that of commercial SiC. During the past decade, AlN particles reinforced metal matrix composites have been extensively studied [15][16][17][18][19][20][21][22][23][24][25][26][27]. Zhanget al [15] investigated the effect of AlN content and preparation process on the structure and properties of AlN p /Cu composites by means of powder metallurgy.…”

“…Sankaranarayanan et al [23]introduced nano-particles into pure magnesium matrix by powder metallurgy, and found a decrement of the thermal expansion coefficient of magnesium matrix. Nam et al [27] synthesized carbon nanotube (CNT)-reinforced aluminum matrix composites by ball-milling and sintering. They concluded that hardened layers formed at the surface of the aluminum-CNT composites as a result of the reaction between aluminum with PCAs and nitrogen.…”