激光选区烧结多孔堇青石/碳纤维复合材料的工艺及性能研究

Process and Performance of Selective Laser Sintered Porous-Cordierite/Carbon-Fiber Composites

通过激光选区烧结(SLS)技术成形了堇青石/碳纤维复合材料初胚,经高温烧结获得了陶瓷试样,研究了陶瓷试样的孔隙率、力学性能和尺寸精度在不同工艺下的变化。结果表明,碳纤维通过烧结颈粘结穿插在堇青石基体中,随着烧结温度的升高,堇青石熔化变形,孔隙率减小。当烧结温度为1350～1400℃时,堇青石为μ相,当烧结温度升高至1425℃时,堇青石由μ相向α相转变。碳纤维有效增强了初胚的韧性和强度,随着烧结温度的升高,陶瓷试样的抗压强度不断增大,并在1425℃时达到最大值5.48MPa。

The green parts of cordierite/carbon-fiber composites are fabricated by the selective laser sintering technique and then the final porous ceramic parts are obtained by high-temperature sintering.The changes of porosity,mechanical performance and dimensional accuracy under different processes are investigated.The results show that the carbon fibers are bonded into the matrix by bonding necks and with the increase of sintering temperature,the cordierite melts and deforms,which leads to the reduction of porosity.When the sintering temperature is 1350-1400℃,the μ-cordierite is stable.In contrast,when the sintering temperature increases to 1425℃,the μ-cordierite is transformed into the α-cordierite.Moreover,the carbon fibers effectively enhance the toughness and strength of the green parts and with the increase of sintering temperature,the compressive strength of ceramic parts increases until to its maximum value of 5.48 MPa at 1425℃.