One of the unique features of Heatric’s heat exchangers is to join flat metal plates through diffusion bonding. Extensive work has been carried out on developing and qualifying robust process procedures for manufacturing this type of heat exchanger.
This paper discusses the important factors affecting diffusion bonding. These include material properties, surface preparation, bonding parameters (pressure, temperature, time and atmosphere) and post bond heat treatment. Material properties will focus on SS316L, 22Cr duplex and alloy 617.
To get ASME approval for using diffusion bonding in the construction of heat exchangers (U stamp certification), the bonding procedure qualification tests must be carried out in accordance with the code requirements. As an example, results from 22Cr duplex test blocks are presented in this paper.
