The quality of the atmosphere inside a sintering furnace plays a key role in the final properties of the sintered part. Properties such as the hardness, ductility, dimensions, carbon content, microstructure and magnetic properties among others are influenced not only by time and temperature, but also by the composition, flow rate and stability of the atmosphere within the furnace. The different physical zones within the furnace require different degrees of oxidizing or reducing power to develop the optimum properties in the final sintered part. Presented in this paper are practical techniques and technologies developed over the last 30 years of experiences with production sintering furnaces. The concept of distributed atmosphere introduction, combined with the use of directional atmosphere injectors, flame curtains, and gas curtains are used to stabilize and maintain the atmosphere profile within the furnace. Optimum and proven designs for atmosphere injectors, flame curtains, gas curtains and exhaust systems are presented.
