Study On The Preparing Of Ferrule Materials For Optical Fiber Connector

In this paper, the materials suitable for the optical fiber connector ferrule weresystematically studied for the first time. The properties of domestic and importedZrO₂ materials were investigated comparatively, and also for the first time, theLi₂O-Al₂O₃-SiO₂ glass-ceramic materials used for the optical fiber ferrule werestudied through powder sintering method. The results showed that the properties ofZrO₂ ceramics were related to the original partial size and its distribution, as well asthe constitution of crystal phase of the ZrO₂ powder. For the Y-TZP ceramics,containing as high tetragonal ZrO₂ as possible in the ZrO₂ powder was beneficial forimproving the strength of ZrO₂ samples, because it may decrease the phasedeformation during sintering. The main reasons resulting in the property differencesbetween domestic ZrO₂ and imported ZrO₂ ceramics were the grain size and crystalphase constitution differences of ZrO₂ powders. The sintering temperatures andthermal expansion coefficients of the ZrO₂ ceramics with LAS glass additives werelowered, compared with the ZrO₂ ceramics, and the lower sintering temperature wasbeneficial to forming finer micstructure in the materials, which was useful to prohibitthe phase transformation under the ferrule processing and further to improve thelow-temperature ageing of the materials and their matching to the optical fiber;Glass-ceramics can be produced by sintering and crystallization of glass powder. Thismethod has many advantages, such as simple process, low equipment investment, lowcost and easy operation, et al. With this method, it is no necessary to introducenucleating agents for preparing the glass-ceramic, because the crystallizationoriginated from the surface of the glass powder, and the glass powder have largerspecific surface, which made the crystallization easier. For LAS glass-ceramics, evenif they have the same main crystal phase β-spodumene s.s., their properties, such asflexural strengths and thermal expansion coefficients of the LAS glass-ceramics couldbe different, because of the chemical composition difference of the main crystal.Additionally, thermal treatment process strongly affected the strength of theglass-ceramic samples;and introduction of a small amount of Bi₂O₃ additive intothe LAS glass-ceramics not only lowered the sintering temperature and porosities ofthe glass-ceramic samples, but also improved the flexural strength and toughness ofthe samples, because the Bi₂O₃ additive promoted the growth of the crystal in longstick shape, and the crystal pinned and dispersed in the glass-ceramic samples, whichhas the strength enhancement effect similar to fiber or whisker in the materials. Theflexural strengths of the glass-ceramic samples were improved obviously by surfacetreatment, because the pressure stress was formed on the surface of the glass-ceramicsamples when Na⁺ came from NaNO₃ replaced the Li⁺ located in the surface of theglass-ceramic samples, it contributed to the mechanical properties improvement ofthe samples. Suitable temperature and treatment time were the important factors toachieve better treatment effect, in my experiment, the strength of the glass-ceramicsamples treated at 360°C for 36 hr was increased by almost 60% compared with theuntreated ones.