Optimization of Parameters Affecting the Quality of Band Saw Blade in Furnace Silver Brazing

Abstract

In this study furnace brazing has been employed in joining the two 2.5 inches high carbon steel band saw blades. The controllable process parameters are brazing temperature, lapping length and filler material plays a very significant role in determining the quality and mechanical properties of a braze joint. In this research work, the objective is to investigate the effect of three process parameters (temperature, lapping length, filler material) on two important mechanical properties viz. tensile strength and hardness of braze joints. A series of experiments has been designed using response surface methodology in Design Expert V 11.0 wherein an empirical relationship between temperature, lapping length, filler material. Using the same methodology an optimized value of the parameters has been obtained which helps the band saw blade run for a prolonged usage. A band saw blade is a saw with an extended, sharp blade consisting of endless band of toothed metal stretched between two or more wheels to chop material. It is primarily used for cutting wood. To use in band saw machine the blades are needed to be joined so that it can be mounted on the pulleys inside the machine. In this project work, furnace brazing is used for joining the blades. Since in the furnace brazing the brazing temperature is greater than the recrystallization temperature of the blade, the properties of the blade material are significantly changed as a result the blades tend to fail near in the joined portion during its operation and may cause accident. The blades may fail due to various reasons such as excessive vibration, fatigue stress, stress concentration, cutting forces, etc. To overcome this failure further optimization is done.