College - Author 1

College of Engineering

Department - Author 1

Materials Engineering Department

Degree Name - Author 1

BS in Materials Engineering



Primary Advisor

Blair London


The effect of residual soldering flux on the mechanical properties of 304 stainless-steel core medical guide wires was analyzed. A soldering process joins the metallic components of the distal end of a medical guide wire product. Acidic soldering flux is used to prepare the surfaces of the metallic substrates. Manufacturing protocol utilizes an ultrasonic bath to remove excess flux from the soldered joints. Sample groups underwent different levels of cleaning: no cleaning, partial cleaning, and full ultrasonic bath cleaning to obtain varying residual flux levels. Experimental sample groups underwent corrosion acceleration in an environmental chamber at 37°C and 85% relative humidity for two 6-hour cycles. Control sample groups were maintained at ambient temperature and humidity. Specimens were tensile tested using a gauge length of 25 cm and a crosshead rate of 10 mm/min on an Instron testing system. A 500-Newton (N) load-cell and 50-N load-cell were used to test the control and experimental groups, respectively. The average maximum loads at fracture obtained by the ambiently exposed samples were 19.52N, 20.1N, and 23.83N for the uncleaned, partially cleaned, and fully cleaned groups, respectively. Experimental sample groups achieved average maximum loads of 13.54N, 13.91N, and 15.31N for the uncleaned, partially cleaned, and fully cleaned groups, respectively. Scanning Electron Microscopy (SEM) was utilized to analyze the presence of corrosion products in one specimen per sample group.