A　continuous-wave　CO2　laser　was　used　to　clad　a　TiC　particle-reinforced　Ni-Cr-B-Si-C　composite　coating　on　to　an　AISI　1045　steel　substrate.　The　microstructure　of　the　clad　was　investigated　by　means　of　X-ray　diffraction,　scanning　electron　microscopy　and　transmission　electron　microscopy.　It　was　found　that　partial　dissolution　of　the　TiC　occurred　on　melting,　and　epitaxial　growth　of　the　remaining　particles　takes　place　by　the　precipitation　of　TiC　upon　cooling.　This　epitaxial　TiC　layer　has　an　additional　alloying　effect　by　using　elements　such　as　chromium　and　silicon　from　the　matrix,　The　pushing　of　TiC　particles　(TiCp)　by　the　solidification　front　causes　them　to　be　unequally　spaced.　Besides　the　TiCp,　the　microstructure　of　the　coating　is　a　mixture　of　feather-like　colonies　and　a　small　amount　of　(gamma-Ni+M32C6)　eutectic.　The　feather-like　colonies　consist　of　CrB　laths　distributed　in　a　gamma-Ni　solid　solution　and　grow　radially　from　the　TIC　particles　because　of　the　large　difference　between　the　thermal　properties　of　TiC　and　the　Ni-Cr-B-Si-C　matrix　alloy.　(C)　1999　Elsevier　Science　S.A.　All　rights　reserved.