The load–displacement response of Banana and Pineapple fibre under quasi-static nanoindentation test through Load control [LC] and Displacement control [DC] modes
The nanoindentation experimentation was performed using Hysitron TI 950 Triboindenter, equipped with three-sided pyramid Berkovich indenter having a tip radius of less than 300 nm. The response curve of the quasi-static nanoindentation test for both displacement control and load control modes are given. The slop of tangent in the response curve at maximum load during unloading yields the stiﬀness of material, which was used to calculate reduced modulus (Er) by using Oliver Pharr method. Under the load control mode, the loading was done from zero to a maximum value of 1000 µN at the rate of 10 µN. After a holding time of 10 sec at the maximum load, the unloading was done at the rate of 20 µN. Under the displacement control mode, the maximum depth of indentation was 1 µm with an indenter displacement rate of 10 nm/s on loading. A hold period of 30 sec was provided after reaching the maximum displacement, and the ﬁbre was unloaded at the rate of 20 nm/s. Notable Findings: 1. The indentation moduli were found to be within the range of 2.7 GPa to 4 GPa for banana ﬁbre, and 3 GPa to 4.5 GPa for pineapple ﬁbre. 2. Hardness was found to be in the range of 0.11 to 0.15 GPa for both fibres.