碳化硅零件的激光选区烧结及反应烧结工艺

SiC Components via SLS Combined with Reaction Sintering

为了获得高密度、高性能、复杂结构的碳化硅陶瓷件,提出采用机械混合法制备含有黏结剂和乌洛托品固化剂的碳化硅复合粉体,对复合粉体进行激光选区烧结(SLS)形成陶瓷素坯,并对素坯进行气氛烧结和渗硅处理,使其与基体发生反应烧结,最终形成复杂陶瓷异形件。实验证明:若激光功率为8.0 W、扫描速率为2 000 mm/s、扫描间距为0.1 mm、单层厚度为0.15 mm,获得的SLS陶瓷样品密度和强度最好。对SLS试样进行合理的中温碳化和高温渗硅,所得碳化硅陶瓷烧结体的抗弯强度最高可达81 MPa,相对密度大于86%。

In order to obtain high density,high performance,complex structures of SiC ceramic parts,a mechanical mixing method was proposed to prepare the SiC composite powder which contained phenolic resin binder and curing agent urotropine.The composite powders in SLS formed the ceramic billets,and the ceramic billet sintering atmosphere and siliconizing processing,making it react with matrix sintering,eventually forming a complex ceramic profiled.When the laser power,scanning velocity,scanning spacing,layer thickness are 8 W,2 000 mm/s,0.1 mm,0.15 mm respectively,the SLS parts have the highest relative density and strength.SLS specimen were degreased and high temperature siliconizing processed reasonably,the bending strength of SiC ceramics sintered parts reached 81 MPa,and the relative density is greater than 86%after high temperature siliconizing process.