Joining material with silicon carbide particles and reactive additives

An assembly comprising:

• a first ceramic or ceramic matrix composite (CMC) part;
• a second ceramic or CMC part adjacent to the first ceramic or ceramic matrix composite part;
• and
• layer of slurry composition between the first ceramic or CMC part and the second ceramic or CMC part, wherein the slurry composition comprises:
• a carrier material;
• and
• a plurality of solid particles in the carrier material, wherein the plurality of solid particles comprises:
• a plurality of first silicon carbide (SiC) particles defining a first average particle size,
• a plurality of second SiC particles defining a second average particles size that is less than the first average particles size, and
• a plurality of reactive additive particles, wherein the plurality of additive particles has a melting temperature that is less than the plurality of first SiC particles and the plurality of second SiC particles,
• wherein the plurality of reactive additive particles are configured to, upon heating to a temperature below a melting point of the plurality of reactive additive particles, react to fuse the plurality of first SiC particles and the plurality of second SiC particles together with the reactive additive particles, and wherein the fused layer of the slurry composition forms a joint layer that joins the first ceramic or CMC part to the second ceramic or CMC part.