Wettability and shear strength of active Sn2Ti solder on Al2O3 ceramics

Purpose - The purpose of this paper is to investigate the wettability of an active Sn2Ti solder on an Al2O3 ceramic material at temperatures of 700 C and higher. Based on the results of the wettability study, soldered joints of Al2O3 ceramics/Sn2Ti solder/steel type AISI 321 were fabricated and the variation of shear strength with time was determined. Design/methodology/approach - For determining melting points, differential scanning calorimetry analysis was performed. The wetting angle of Sn2Ti solder on Al2O3 ceramics was measured using specially developed equipment with a 10-3 Pa vacuum at temperatures of 700, 800, 850 and 900 degrees C. The wetting angle on AISI 321 steel at a temperature of 850 degrees C was also determined. The joints of Al2O3 ceramics/Sn2Ti solder/steel type AISI 321 were prepared at 900 degrees C, in a vacuum for times 5, 10, 15 and 20 min. Findings - The best wettability of Sn2Ti solder was achieved at a temperature of 900 degrees C. The wetting angle at the parameter of 900 degrees C/ for 15 min was 47.5 degrees. The joints of Al2O3 ceramics/Sn2Ti solder/steel type AISI 321 attained a strength of 18.3 MPa. It was found that the microstructure of Sn2Ti solder consists of a tin matrix with the presence of a alpha Ti6Sn5 phase. Originality/value - The results of the work are of significance for the further development of soldering with active solders in a vacuum, as well as with the application of power ultrasound. The possibility of soldering Al2O3 ceramics with SnTi-based solders was thus demonstrated.