Journal of Powder Materials

Research Article

[Korean]
Pressure-Dependent Resistivity of Commercial Nickel Powders with Different Morphologies and Sieve Classes for Pressure-Conductive Rubber Semiconductor Test Sockets: DongWook Lee, Moonjung Kim; J Powder Mater. 2026;33(5):379-387. Published online October 30, 2026; DOI: https://doi.org/10.4150/jpm.2026.00255

Abstract PDF Supplementary Material: Pressure-conductive rubber (PCR) sockets rely on Ni powder fillers. We characterized four commercial Ni powders of two morphologies (spherical and dendritic) and two sieve classes (25–32 and 32–45 μm) using laser diffraction, N₂ adsorption, He pycnometry, scanning electron microscopy, and four-point powder resistivity at 2.6–25.7 MPa. Sieve subclassification had little effect on specific surface area, true density, or resistivity, whereas the spherical and dendritic groups differed markedly; as the two morphologies came from different suppliers, this is a combined morphology/supplier effect. Dendritic powders conducted in all three replicates at the lowest pressure (2.6 MPa), whereas spherical powders did so only from 10.3 MPa, with partial conduction at 7.7 MPa. At matched pressures, the groups differed by a factor of 16–70 (1.5 vs 86 mΩ•cm at 25.7 MPa). Despite lower packing fractions, dendritic powders had lower resistivity, consistent with contact topology, not packing density, governing conduction. With residual resistivity fixed at the bulk Ni value, the Montes compaction model described all specimens (R² = 0.986–0.996) with group-dependent exponents (n ≈ 2.1 dendritic, 3.2–3.9 spherical). These findings support using pressure-dependent powder resistivity to prescreen candidate Ni fillers before PCR socket prototyping.

Article

[Korean]
Manufacturing and Evaluation of Properties of Nanocrystalline Ni bulk by Dynamic Compaction of Nano Ni powders using a Gas-gun System: Wooyeol Kim, Dong-Hyun Ahn, Lee Ju Park, Jong-Il Park, Hyoung Seop Kim; J Korean Powder Metall Inst. 2014;21(1):44-49. Published online February 1, 2014; DOI: https://doi.org/10.4150/KPMI.2014.21.1.44

Abstract PDF: In this study, nanocrystalline nickel powders were cold compacted by a dynamic compaction method using a single-stage gas gun system. A bending test was conducted to measure the bonding strengths of the compacted regions and microstructures of the specimen were analyzed using a scanning electron microscopy. The specimen was separated into two parts by a horizontal crack after compaction. Density test shows that the powder compaction occurred only in the upper part of the specimen. Brittle fracture was occurred during the bending test of the compact sample. Dispersion of shock energy due to spalling highly affected the bonding status of the nanocrystalline nickel powder.

Search