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Fabrication of Al 2 O 3 ‐SiO 2 ceramics through combined selective laser sintering and SiO 2 ‐sol infiltration
Author(s) -
Li ChenHui,
Hu Liang,
Zou Yang,
Liu JiangAn,
Xiao JianHua,
Wu JiaMin,
Shi YuSheng
Publication year - 2019
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13353
Subject(s) - materials science , cristobalite , sintering , microstructure , ceramic , mullite , composite material , selective laser sintering , quartz , shrinkage , fabrication , laser , mineralogy , optics , medicine , alternative medicine , physics , pathology , chemistry
In this study, different posttreatment methods, including silica‐sol infiltration (SI), vacuum silica‐sol infiltration (vSI), debinding (DB), and pressure‐less sintering (PS), were combined with selective laser sintering (SLS) to fabricate Al 2 O 3 ‐SiO 2 ceramics. The macro‐morphology and microstructure of sample fabricated under different laser processing parameters and posttreatment process were investigated. Results show that the geometric dimension accuracy and surface quality of the final samples can be effectively improved with appropriate SLS parameters and posttreatment. The optimal SLS processing parameters are determined to be 0.15 mm, 10 W, 0.1 mm, and 1500 mm/s for the hatch spacing, laser power, layer thickness, and scanning speed, respectively. The SLS/DB/vIN/FS samples have the smallest linear shrinkage ratio (<1%), the least warpage degree (<3%), and the best surface quality (surface altitude difference <170 μm). Mullite, quartz, corundum, and cristobalite composed the phases of the sample, of which cristobalite came largely from the infiltrated silica‐sol. Since a higher amount of silica‐sol infiltrated into the sample under SLS/DB/vIN/FS process, more cristobalite phase formed in the pore of the sample during sintering, which avoided excessive microstructure shrinkage during sintering and ensured the high geometric accuracy and surface quality of the final sample.