Micro-Compression Characterization and Thermal Stability of Electrolessly Plated Nickel Phosphorus Alloy

• Published in: ECS journal of solid state science and technology Vol. 10; no. 3; p. 35007
• Main Authors: Hotta, Tokihiro, Chang, Tso-Fu Mark, Chen, Chun-Yi, Sawae, Hidekazu, Imada, Yu, Mizoguchi, Masanori, Kudo, Osamu, Maeda, Ryu, Sone, Masato
• Format: Journal Article
• Language: English
• Published: 01.03.2021
• ISSN: 2162-8769; 2162-8777
• DOI: 10.1149/2162-8777/abedd3

The micro-compression characteristic of an electrolessly plated Ni-P alloy was evaluated in this study. Specimens used in the micro-compression test were micro-pillars having a square cross-section fabricated by focused ion beam system. One side of the square cross-section was varied from 5 to 20 μ m and the aspect ratio of the micro-pillars was kept at 2:1 to evaluate the sample size effect on the mechanical property. The as-plated Ni-P alloy was amorphous. The sample size effect commonly observed in mechanical properties of metallic micro-specimens was not obvious for micro-pillars fabricated from the as-plated Ni-P alloy, and all of the micro-pillars showed shear band deformation with the 0.2% yield strength at roughly 2.2 GPa. Heat treatment was conducted to study the influence on the sample size effect. After heat treatment at 300 °C for 2 h, an increase in the strength was observed in micro-pillars with all sizes. In addition, for the heat-treated specimens, the fracture strength increased from 3.1 to 4.7 GPa when cross-section of the micro-pillar decreased from 20 × 20 to 10 × 10 μ m 2 , which revealed the sample size effect.