Selective Area Laser Deposition For The Purpose Of Ceramic Joining And Repair

Ceramic materials present joining and repair difficulties that metallic and polymeric materials often lack. The high working temperature and potential for thermal decomposition make techniques such as welding and adhesive bonding unfeasible or impractical. It is possible to create ceramic materials from gas phase precursors through the use of chemical vapor deposition methods. A laser can create localized heat in a substrate and cause the productive decomposition where spatially desired. Through computer motion control, arbitrary patterns of ceramic deposits can be grown. This technique can be used to make free form objects. This process is known as selective area laser deposition (SALD). A similar process of selective area laser deposition and vapor infiltration (SALDVI) uses a powder bed to create more uniform depositions. Through the use of these techniques, while defining the negative space of a joint as the envelope for a three dimensional deposit, it is possible to form a joint fill. The process can be used to create a variety of ceramic compositions by manipulating the precursor gas combinations. The design of a deposition-joining system is presented. The system is operated as a proof of concept to create, silicon carbide, silicon nitride and aluminum oxide deposits and joints. These different systems are characterized to show the potential for this technology