Elastoplastic nanoindentation behaviors of sintered nano-silver under various sintering parameters

Abstract

Purpose This study aims to characterize the mechanical properties of sintered nano-silver under various sintering processes by nano-indentation tests. Design/methodology/approach Through microstructure observations and characterization, the influences of sintering process on the microstructure evolutions of sintered nano-silver were presented. And, the indentation load, indentation displacement curves of sintered silver under various sintering processes were measured by using nano-indentation test. Based on the nano-indentation test, a reverse analysis of the finite element calculation was used to determine the yielding stress and hardening exponent. Findings The porosity decreases with the increase of the sintering temperature, while the average particle size of sintered nano-silver increases with the increase of sintering temperature and sintering time. In addition, the porosity reduced from 34.88%, 30.52%, to 25.04% if the ramp rate was decreased from 25°C/min, 15°C/min, to 5°C/min, respectively. The particle size appears more frequently within 1 µm and 2 µm under the lower ramp rate. With reverse analysis, the strain hardening exponent gradually heightened with the increase of temperature, while the yielding stress value decreased significantly with the increase of temperature. When the sintering time increased, the strain hardening exponent increased slightly. Practical implications The mechanical properties of sintered nano-silver under different sintering processes are clearly understood. Originality/value This paper could provide a novel perspective on understanding the sintering process effects on the mechanical properties of sintered nano-silver.