Our company is a domestic enterprise that only produces pure zirconia ceramic cylinder liners. We have jointly developed and invented them with Tianjin University and have practical applications.     The ceramic cylinder liner outer sleeve is made of 45 # forged steel, and the ceramic inner sleeve is made by our company's own batching, pressing, and sintering. The material ratio is strictly controlled, and the inner sleeve is made of 95% zirconia and 5% yttrium oxide. Ensuring the high purity of zirconia in the ceramic cylinder liner is the key to its service life. After sintering, it is processed by grinding and forging to match the interference fit of the outer sleeve, and then processed into the finished product. Adopting API standard tolerances, with a normal service life of over 4000 hours.     The tracking number of ceramic cylinder liners can trace the original smelting number of each cylinder liner forging outer sleeve, the original firing record of the inner sleeve, and the dimensional records of each part.