1. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Preliminary Uncoated Glass-to- Glass Bonding Tests with Indium Foil M. E. Kupfer A.G. Raraz J. E. Indacochea 23 June, 2010

2. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Objectives Establish experimental steps. Establish a proper samples arrangement. Determine optimum experimental parameters such as loading force.

3. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Experimental Setup Schematic Static plate Hydraulic loading force Glass samples Indium foil Steel sheets for uniform distribution of applied force

4. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Experimental Parameters Indium foil was made in-house by rolling indium wire. Oxide layer was scraped off under a minute before pressure was applied. 6000 psi was applied for 10 minutes. In air and room temperature.

5. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Experimental Arrangements Wall-to-Wall samples Window-to-Window samples Wall-to-Window samples (sandwich) Wall-to-Window Wall section sample Window section sample

6. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Glass-to-glass bonding The strength of the bond was not determined; however it is strong enough to resist tugging.

7. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Glass samples cracking At a load force of 6000 psi, the wall section sample cracked and the pieces are still bonded. Glass pieces are uncoated!!! In other tests, window section samples began cracking at 1000 psi.

8. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Loading force Using a rubbery material to have a uniform distribution of the loading force was not successful. Other materials are going to be tested. Hydraulic press was not holding pressure more than 10 minutes. Its replacement may be necessary asap.

9. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Tests Results Summary Using uncoated glasses was helpful to establish some bonding tests arrangement. Uniform distribution of the load force is still an issue to be determined. The different cracking loads corresponding to the two types of glass samples is going to limit the applied force, so far, to less than 1000 psi.

10. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Work in progress Dean will provide coated B33 flat samples this week (coated chromium and indium layers). We will coordinate with Dean for best bond results based on thickness of coatings. Improve samples arrangement to eliminate cracking (a better uniform distribution of the loading force).

11. T h e U n i v e r s i t y o f I l l i n o i s a t C h i c a g o Joining Science and Advanced Materials Research Laboratory Samples Data Effective bonding area: 1.2 cm x 0.47 cm = 0.56 cm 2 0.48” x 0.185” = 0.089 in 2 Thickness of window sample = 0.263 cm (0.1”) 6000 psi x 0.089 in 2 = 534 pounds 1000 psi x 0.089 in 2 = 89 pounds