The Effect Of Environmental Conditions On The Strength Of A Laser Weld

The primary objective of the experiment was to determine the effects of high and low temperatures and water submersion on the strength of a laser weld on two different carbon based polymers, when compared to room temperature. This was done by finding the individual maximum stresses of each polymer coupon. After each set comprising of a transmissive (without pigment) coupon and absorptive (with pigment) coupon were laser welded together, they were exposed to 80 degrees Celsius, -40 degrees Celsius, or water submersion. Next, the coupon pairs were clasped onto the lap shear load frame and were pulled in opposite directions until they separated. The load frame machine calculated the maximum load, while the area of the absorptive coupon's weld was found using a computer program called Image Pro Plus. The maximum stress, measured in mega-Pascals, was calculated by dividing the maximum load by the area of the weld. Following the data collection, the analysis of multiple graphs and scatter plots showed that high and low temperatures did have an effect on the strength of a laser weld, but the exposure of water did not have an effect. In other words, cold temperatures required more stress to weaken a weld, while hotter temperatures required less stress. Water, on the other hand, had no effect whatsoever on the strength of a laser weld.

Research Done By:

Afroze Ahmed
Sterling Heights High School

Michael Polselli
Fraser High School