Fabrication and high-temperature properties of Y-TZP ceramic helical springs by a gel-casting process

A rectangular cross-section ceramic helical spring of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) was prepared by the gel-casting process. Both the compressive curves and comprehension rebound curves were tested at room temperature and high temperature. The results showed that springs obeyed Hooke׳s Law at room temperature, as the compression resilience ratio of the samples was nearly 100% under the condition of spring׳s security and no damping loss occurred during the process. Besides, mechanical failures of springs occurred under loads around 128 N with the deformation of 10%. With increasing test temperature the maximum load-carrying capacity of the spring decreased, while the maximum deformation increased. Besides, the load–compression curve showed a yield step when the test temperature was above 800 °C. At elastic stage of spring under high temperature, the compression resilience ratio was also nearly 100%; however, the anelastic effect took place and energy loss increased with the increase in test temperature.