combustion at a stable speed to achieve a certain delay time of combustion. It is mainly composed of oxidizer, reducing agent (combustible agent), adhesive and burning rate regulator, and is usually pressed into the housing, or made into columns and delay cables. It can be divided into silicon type delay composition, boron delay composition, tungsten delay composition, and organic delay composition delay composition according to different combustible composition; According to the presence or absence of gas during combustion, it can be divided into three categories: presence of gas, micro gas and absence of gas. The burning rate with gas is greatly affected by external pressure; According to the delay time, it can be divided into microsecond level (instantaneous delay composition), millisecond level (short) and second level (long). The delay time mainly depends on the burning rate and length of the column. The main technical requirements are stable burning rate and accurate combustion transfer time. It has reliable function, good physical chemistry stability, low mechanical sensitivity and simple process. The main factors affecting the burning rate and accuracy are the composition and proportion of the propellant, the intensity of the pilot flame, the ambient temperature, the purity and particle size of the raw materials, the density of the pressurized propellant, and the constraint conditions. The evaluation parameters mainly include delay precision (ignition point), burning rate and output energy. Mainly used for time fuses, self destruct devices, release mechanisms, delay detonators, delay igniters, etc.
Energy Materials -> Energetic materials -> Pyrotechnic agents