A Study of Fusion Layer in Explovive Bonded Boundary (Report 2)

Abstract

The formation of a fusion layer (or alloy) on the bonded boundary in explosive bonding was discussed in this paper. For various combinations of dissimilar metals made by explosive bonding, the constitutionn of fusion layer at an interface was determined by x-ray microanalyser, then this measured value was corrected using absorption coefficient, etc. and a true value of the constitution was found (Table 1).
Assuming that momentarily heat was supplied at the interface of dissimilar metals, successively these metals were melted by the conducted heat, and the rate of melted volume was given by the equation (calculated value A, Table 1).
m₁/m₂=√λ₁c₁ρ₁/λ₂c₂ρ₂ ⋅ c₂(θm₂-θ₀)+Hm₂/c₁(θm₁-θ₀)+Hm₁
λ; heat conductivity c; heat capacity ρ; density θm; melting point θ; room temperature Hm; latent heat
From the former equation, assuming that equivalent heat was generated in metals near the interface, the rate of melted volume of these metals was given by the equation (calculated value B, Table 1).
m₁/m₂=c₂(θm₂-θ₀)+Hm₂/c₁(θm₁-θ₀)+Hm₁
The averaged values (=A+B/2) of (A) and (B) well agreed with the measured values (Fig. 7).
The result showed that heat was generated at the interface and at the inner metal near interface by plate impact, then the heat was conducted and it melted these metals of interface.
Under combination of metals having a large difference of melting points, the melting point of layer was substituted for those of metals, so that the calculated value became equal to the measured value.