Page 105 - eBook_Proceedings of the International Conference on Digital Manufacturing V2

Fabrication and Characterization of a Low-Cost Piezoelectric using Rochelle
Salt for Energy Harvesting and Sensor Applications

Lastly, the semi-solid billet was forged to form the claw pole
using a top and bottom die setup. Findings show that the optimal
process parameters for preparing low-carbon steel semi-solid
billets with fine and globular microstructures (Figure ) were
identified with an area reduction rate of 67%, an isothermal
temperature of 1500 °C, and a holding time of 15 minutes (Li,
Wang, Li, Liu & Zhao, 2023).

The low-carbon steel claw pole fabricated using optimised
parameters exhibited significant improvements in mechanical
properties, with yield strength and tensile strength increasing by
88.5% and 79.8%, respectively, compared to the base materials.
Analysis of effective strain and stress distributions revealed that
higher area reduction rates contributed to improve forging quality.
Despite these advancements, the study highlighted key
challenges, particularly in achieving the desired microstructure
due to the narrow semi-solid temperature range and the difficulty
of controlling oxidation during high-temperature isothermal
treatment. It was also difficult to ensure the dimensional accuracy
and mechanical properties of the final product (Li, Wang, Li, Liu
& Zhao, 2023).

Figure 40: Process diagram of the SSTFF method for the claw pole:
(a) initial deformation stage, (b) isothermal treatment stage, and (c)
final forming stage (Li, Wang, Li, Liu & Zhao, 2023).

89