A new design of zirconia induction furnace for production of high-strength fiber

A newly designed zirconia induction furnace consisting of two different zirconia tubes, of which the inner one is partially coated with thin silica film, was evaluated in terms of the strength of drawn fibers. The results of 47-km length of the prooftested fibers demonstrated superb performance, producing a high-strength fiber. The average survival length that passed the prooftest level at 200 kpsi is ∼ 8 km. According to scanning electron microscope (SEM) analysis, there is no indication of zirconia particles deposited on the fiber surface, which is commonly observed in the fibers drawn with the existing single-tube zirconia furnace. In this case, most of the breaks are due to a bubble in the coating.