Cuprous azide impact sensitivity

Martin carried out extensive research into the explosive properties of the azides of various metals (Table 33). The high sensitiveness of cuprous azide to impact is noteworthy. 

A recent study of the sensitivity of cuprous azide to heat and impact by Singh (Ref 20)... 

A recent study of the sensitivity of cuprous azide to heat and impact by Singh (Ref 20) confirms earlier investigations showing that sensitivity increases with an increase in cryst size. The activation energy involved in its thermal decompn has been established as 26.3 k cal (Ref 20). In addn to heat of deton, temp develpd on exp In, work density and loading density, Wohler Martin (Refs 6 7) also report the following info with respect to the initiating efficiency of CuNsi... 

The impact sensitivity of three fonns of cuprous azide, obtained by a ball-drop technique, are shown in Figure 10. Singh [35] found that cuprous azide... 

Figure 10. Impact sensitivity of cuprous azide on a ball-drop apparatus [35] 7/8-in. ball 15 trials at each height.

Copper forms two azides cuprous azide or copper (I) azide, and cupric azide or copper (II) azide. Cuprous azide, Cu2(Nb)2, MW 211.14, CAS [14336-80-2] is a colorless crystalline solid. It is highly sensitive to impact. It explodes on heating. It decomposes at 205°C (401°F). The heat of formation [AH (i)] is reported as 253.1 kJ/mol (60 kcal/mol) (Bretherick 1995). 

Singh, K. Sensitivity of cuprous azide towards heat and impact. Trans. Faraday Soc. 55, 124-129 (1959)... 

Cuprous and cupric azides are very sensitive to impact and friction [15, 21, 101, 102]. Sensitivity of cuprous azide CuNs depends on the crystal size (Fig. 2.17). The larger crystals of CUN3 ( 3 mm) may explode even by the touch of a feather [5]. 

The sensitivity of normal and basic cupric azides to impact varies significantly. The impact sensitivity is represented in Table 4.9 showing that cuprous and cupric azides are more sensitive than LA. Monobasic cupric azide is reported to be more sensitive than LA according to Kabik and Urman [49] and Lamnevik [107] while Fedoroff s encyclopedia reports its sensitivity lower than LA [5]. Basic cupric azides with two or more bases are less sensitive to impact than LA [107]. 

---