Airbag popping out

Pyrotechnics

In the automotive industry pyrotechnics are used in many applications such as airbags and belt pretensioners.

In powdered form, titanium and zirconium are corrosion-resistant to a remarkable degree and, in contrast to other commercial metal powders, they are also stable for long periods of time when kept under regular conditions of storage. Coupled with this stability is a high degree of chemical reactivity at a slightly elevated temperature. Combustion in air is rapid, and accompanied by the evolution of much heat and light. In mixture with an oxidizing agent (e.g. KClO4, Ba(ClO4)2), titanium and zirconium form a very reliable composition that ignites easily and produces a high energy output, along with the discharge of numerous hot particles. Such behavior makes titanium and zirconium powders very useful as fuel in ammunition elements. Titanium and zirconium constitute a heat source for squibs and ignition devices in a variety of uses, including automotive airbag igniters and inflators.

In some pyrotechnic applications titanium and zirconium are introduced in the shape of their respective hydrides, i.e. TiH2 and ZrH2.

A zirconium/nickel (Zr/Ni) alloy is used as a fuel in delay compositions because of its slow and reliable burning characteristics. In addition, compositions containing Zr/Ni alloys and an oxidizing agent react without producing gas.