Authors : S. Mir Mohammad Rezaei , F. Gramipanah , A. Fallahi Arezodar and A. Amini
Abstract: Fatigue failure of base metal solder joints are an unsolved problem and information relating to the fatigue strength of solder joints is rarely provided. The purpose of this report is to test the application of Vera solder for use with the base metals of Verabond II and Minalux and its effect on fatigue behavior of these joints. Fifteen cast and 12 soldered joint specimens were made of each alloy. The thermal cycles required for oxidation, opaque, dentin and glazing were performed. Rotating, bending and cantilever fatigue tests were performed with a 2880 rpm (ASTM Rotating bending fatigue testing of metals JIsz 22 74;1078). All soldered specimens except two in each group fractured at soldered joints. All of the specimens from intact Verabond II and Minalux fractured at the gripping point of machine except two Minalux specimens that fractured at the midpoint. Under equal load, the number of loading cycles to cause fracture in intact Verabond II is greater than in intact Minalux. In soldered Verabond II the fatigue limit was 20 MPa higher than in soldered Minalux. With probability of 90% and with Confidence Interval (CI) of 90% the fatigue limit of soldered Minalux is 194.65MPa and for soldered Verabond 2, it is not possible to give a probability. The Fatigue Ratio of soldered Verabond 2 is 0.57 and Minalux 0.50. Due to the influences of several parameters, with use of the gas-oxygen torch, the resulting solder especially in base metal alloy is not reliable. As a result, Vera solder alloy by gas-oxygen torch is not recommended for Verabond II and Minalux.
S. Mir Mohammad Rezaei , F. Gramipanah , A. Fallahi Arezodar and A. Amini , 2008. Fatigue Properties of Soldered Minalux and Verabond II Ni Base Dental Alloys. Research Journal of Biological Sciences, 3: 690-696.