BS in Materials Engineering
Materials Engineering Department
Dr. Trevor Harding
An experiment was conducted to determine and reduce the causes of variation between a 304 Stainless Steel and super elastic Nickel Titanium dissimilar metal weld. Six factors were established to understand the cause of variation: perpendicularity, final grind, surface finish, weld force, weld pulse duration, and alignment. Using a rotational test with an air piston break pressures were established and charted in Minitab to identify trends. It was shown that weld force and weld pulse duration were the two factors that had the most influence on break strength. This data also showed that higher strength groups had less variability. So strength had to be maximized. SEM, BSE, and EDS were used to determine material differences at the interface. There were three instances of possible intermetallic compounds that need to be examined further.