Pure　alumina　(99.9%　grade　compositions)　was　brazed　to　4J33-Kovar　alloy　based　on　PTLP　technique　with　nickel　and　titanium　foils　interlayer.　The　solder　formed　a　sandwich　microstructure:　an　alpha-Ti　solid　solution　belt　at　mid　part　and　Ti2Ni　intermetallics　belts　at　two　sides.　This　structure　accounts　for　the　good　property　of　the　joint.　Microanalysis　identified　a　reaction　product　at　the　aluminabraze　interface　as　Ni2Ti4O　phase.　The　special　properties　and　structural　compatibility　of　Ni2Ti4O　contributed　to　the　firm　joint.　The　effects　of　brazing　conditions　on　the　joint　properties　were　investigated.　The　joint　shear　strength　showed　the　highest　value　of　about　65MPa　and　did　not　monotonously　increase　with　the　brazing　temperature　ascending.　It　was　shown　that　extending　of　brazing　time　gave　thicker　reaction　layer　and　higher　joint　strength.　(C)　2002　Elsevier　Science　Ltd.　All　rights　reserved.