Effects of binders on dimensional accuracy and mechanical properties of SiC particulates preforms fabricated by selective laser sintering

SiC preforms were produced by selective laser sintering and thermal treatment sintering at 700 °C for fabricating near-net-shape composites. The dimensional accuracy and mechanical properties were investigated. The results show that dimensional accuracy 98.42% of preforms was obtained. After sintering at 700 °C, the dimensional accuracy of preforms using the binder of epoxy resin was decreased obviously, but that using the binder of epoxy resin and NH4H2PO4 was maintained. The tensile and bend strength of preforms using epoxy resin and NH4H2PO4 as binder were higher than that using epoxy resin, and enough to support the external load. When the epoxy resin was decompounded at 700 °C, the reaction product of SiP2O7 phase can form an effective bonding for maintaining the dimensional accuracy and supporting mechanical properties of preforms by using the binder of epoxy resin and NH4H2PO4.