Abstract
Copper bars were soldered along their length with a thin layer of lead-free Sn3.0Ag05.Cu alloy under standard surface mount processing conditions to prepare double cantilever beam (DCB) specimens. The geometry of the DCBs was varied by changing the thickness of the solder layer and the copper bars. These specimens were then fractured under mode-I and two mixed-mode loading conditions. The initiation strain energy release rate, Gci, increased with the relative fraction of mode-II, but was unaffected by the changes in either the substrate stiffness or the solder layer thickness. However, the steady-state strain energy release rate, realized after several millimeters of crack growth, was found to increase with the solder layer thickness at the various mode ratios. The crack path was found to be influenced by mode ratio of loading and followed a path that maximizes the von Mises strain rather than maximum principal stress. Finally, some preliminary results indicated that the loading rate significantly affects the Gci.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1169-1181 |
| Number of pages | 13 |
| Journal | Engineering Fracture Mechanics |
| Volume | 78 |
| Issue number | 6 |
| DOIs | |
| State | Published - Apr 2011 |
| Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering
Keywords
- Crack path
- Fracture
- Lead-free solder
- Loading rate
- Mixed-mode
- R-curve
- Stiffness
- Strength
- Thickness