Microstructure and mechanical properties of Sn–Cu alloys for detonating and explosive cords

ABSTRACT

To develop alloys as the substitute of Pb-based alloys for cladding materials in detonating and explosive cords, the materials requirement was analysed and Sn–Cu based alloys were selected as potential candidates. Four alloys including Sn–0.3 wt-%Cu, Sn–0.5 wt-%Cu, Sn–0.7 wt-%Cu, and Sn–1.0 wt-%Cu were prepared by casting and rolling. Microstructures of as-cast Sn–Cu alloys comprised Sn solutions with Cu6Sn5 intermetallic in the matrix. The as-rolled hypoeutectic Sn–Cu alloys (0.3–0.5 wt-%Cu) offered the yield strength from 26.1 to 31.9 MPa, UTS from 30.1 to 34 MPa and elongation from 86.4 to 87.5%, which were found to be appropriate for detonating and explosive cords. Particularly, the Sn–Cu alloys exhibited strain softening behaviour under tensile stress, which will benefit cladding manufacture and subsequent processing after assembly with high-energy explosive materials.

KEYWORDS:

• Sn–Cu alloys
• microstructures
• mechanical properties
• rolling
• detonating and explosive cords

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support from the National Aerospace Technology Exploitation Programme (NATEP) and Chemring Energetics UK [grant number WEAF058] is gratefully acknowledged.