Effect of surface porosity on ceramics during Al 2 O 3 /Ti bonding through brazing

For this work two Al 2 O 3 /Ti sandwich arrangements were joined by brazing method using a Ti 60 Cu 40 sheet as joining element. The first arrangement used an Al 2 O 3 ceramic compact with high densification (95%), meanwhile and the second arrangement used a porous compact, named Al 2 O 3 -95 and Al 2 O 3 -63 respective. The temperatures used in the process were 1000 and 1040 °C during 1 to 10 min, under argon atmosphere. The joining results of the Al 2 O 3 -95/Ti 60 Cu 40 /Ti system showed a metallic interface with precipitates of Ti and Cu formed from the metallic foil. This interface had an average hardness of 254 HV. Moreover, the Al 2 O 3 -63/Ti 60 Cu 40 /Ti joining system formed an interface composed of a Ti-Cu matrix with Al 2 O 3 , similar to the assemblies made with ceramic reinforcing particles. The hardness in arrangement reached more 1900 HV on the interface, that result is similar to the showed in composites with metal matrix of titanium or copper. Graphical abstract