BONDING AND PROCESSING TECHNIQUE OF LAMINATED COMPOSITE MATERIALS

Document Type : Original Article

Authors

1 Assistant Lecturer, Dpt. of Material Sc. and Engineering, Military Technical College.

2 Professor, Dpt. of Material Sc. and Engineering, Military Technical College.

Abstract

An optimum composite technology by diffusion bonding was developed to obtain aluminum-laminated composites. Pure aluminum and duralumin laminates that have distinct properties were bonded together without the use of an intermediate binding layers or using pure Cu or Brass as intermediate layers by applying the hot pressing technique. The effect of hot pressing parameters (P,T & t) were studied from the microstructural point of view. Also, the micro chemical analysis was carried out to follow the evolution of diffusion of the different elements in the interdiffusion zone under different parameters to predict the phases that may be formed through it. The mechanical properties of the produced laminated composites, before and after age hardening, were studied. The results obtained from the microstructural analysis revealed that, binding of both laminates without using a binding material can be achieved at an optimum conditions of P=54MPa, T=500°C & t=5hrs. Excessive diffusion of copper atoms from the duralumin laminate towards the pure aluminum was recorded and attained an average depth of 135pm. This bleeding of copper atoms leads to a substantial decrease of the mechanical properties of the duralumin side. On the contrary the application of an age hardening cycle leads to an increase of hardness from 90 to 240 VHN in the duralumin laminate. To retain the level of the copper atoms in the duralumin and in the same time to secure enough diffusion that allows sufficient bonding between both laminates a copper layer of 10pm thickness was used as a binding material. Using of brass as a binding material provided a better binding effect where zinc enhances copper atoms to penetrate in the brass intermediate layer towards the pure
laminate.

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