- [English]
- Microstructure and Properties Comparison of Pure Cu and Cu-5 wt.% Al2O3 Composite Processed by Spark Plasma Sintering
-
Dinh Van Cong, Dong-Wan Lee, Su-Wan Lee, Nguyen Minh Thuyet, Nguyen Viet Hoang, Jin-Chun Kim
-
Received December 3, 2025 Accepted February 25, 2026 Published online February 26, 2026
-
DOI: https://doi.org/10.4150/jpm.2025.00472
-
-
 Abstract
- This study compares the microstructure and properties of pure Cu and Cu-5 wt.% Al2O3 composites fabricated by spark plasma sintering under strictly identical processing conditions at 800-1000 °C. Pure Cu samples achieved near-full densification and exhibited a bimodal grain structure dominated by coarse grains with increasing sintering temperature. In contrast, the composite samples showed lower density and non-monotonic densification behavior, with a minimum relative density at 900 oC and significantly refined equiaxed grains due to strong grain-boundary pinning by nano Al2O3 particles. The higher fractions of high-angle boundaries and pronounced orientation disruption were observed in the composite samples, while high-resolution analysis confirmed the presence of grain-boundary Al2O3-rich regions that restricted Cu grain coalescence and continuity of grain boundary migration. X-ray diffraction results confirmed the absence of reaction phases in both materials. Hardness peaked at 900 °C for both samples, and the composite samples showed consistently lower hardness due to retained porosity. The apparent electrical conductivity of the composite displays a non-linear temperature dependence, reflecting the competing influences of densification, microstructural recovery, and the insulating nature of Al2O3.
- [English]
- Microstruture and Mechanical Properties of Ti.Grade12-Ti/TiN/WC Composite produced By Spark plasma sintering Process
-
Hyun-Su Kim, Su-Gwan Lee, Dinh Van Cong, Jun-Seo Park, Ha-Seung Ryu, Jin-Chun Kim, Seung-Ick Lee
-
Received December 5, 2025 Accepted February 23, 2026 Published online February 26, 2026
-
DOI: https://doi.org/10.4150/jpm.2025.00486
-
-
Abstract
- Ti.Grade12 is widely used in chemical processing, power generation, and nuclear industries because of its excellent corrosion resistance and mechanical strength, enhanced by alloying elements such as Ni and Mo. Ceramic reinforcements such as TiN have been reported to significantly improve the surface hardness and wear resistance of titanium-based materials. Furthermore, nano-sized WC particles can suppress excessive intermetallic compound formation and stabilize the Ti matrix through grain boundary pinning and microstructural control mechanisms. However, strong interfacial bonding between Ti and ceramic reinforcements generally requires high temperatures and prolonged sintering times, which may induce undesirable secondary phase formation. Therefore, optimizing the mixing ratio of Ti, TiN, and WC is essential to achieve a homogeneous interface and a stable composite structure. In this study, a composite layered structure was fabricated on a Ti.Grade12 substrate using mixed Ti, TiN, and nano-sized WC powders via Spark Plasma Sintering. A composition of 60 wt% Ti, 35 wt% TiN, and 5 wt% WC formed a stable coating layer without secondary phases and achieved a micro vickers hardness of approximately 2400 Hv.
|
KPMI
