Method for testing propellant loading heat insulating layer material volume expansion coefficients according to liquid infiltration method

Abstract

The invention discloses a method for testing propellant loading heat insulating layer material volume expansion coefficients according to a liquid infiltration method. According to the method disclosed by the invention, firstly, three propellant loading heat insulating layer test pieces are prepared through processing, a volume expansion coefficient testing device is calibrated with an inert liquid, a liquid volume change value is measured in a heating state so as to calculate a liquid expansion coefficient, calibration does not need to be performed every time, and only one calibration is performed when the temperature change is little, the interval time is short and the inert liquid belongs to the same batch; after the calibration steps are completed, the heat insulating layer test pieces to be tested are totally immersed into the inert liquid, the total volume change value of the liquid and each heat insulating layer test piece to be tested is measured in the heating state, and the thermal expansion temperature coefficients of the solid samples (namely the heat insulating layer test pieces ) to be tested can be obtained as the liquid thermal expansion temperature coefficient is stable. Through the method, direct and accurate measurement of the material volume expansion coefficients can be realized, the requirement on an operator is low, and a tested result can quickly and accurately reflect the situation of the samples.

Description

[0001] The invention belongs to the field of propellant technology, and mainly relates to a method for testing the volume expansion coefficient of a propellant charge heat insulating layer material. Background technique [0002] The coefficient of volume expansion refers to the deformation of a material per unit volume at a unit temperature. Theoretically, the volume expansion coefficients of the thermal insulation layer, the lining layer and the propellant grain should be basically equal in value, so that the volume deformation of the thermal insulation layer, the lining layer and the grain under long-term storage conditions are consistent. On the contrary, the volume expansion coefficients of the insulation layer, the lining layer and the grain column are quite different, so that the volume deformation of these three parts is quite different during the long-term storage process, the local stress between the contact surfaces increases, and the fit deteriorates, resulting in D...

AI Technical Summary

Problems solved by technology

[0005] At present, the widely used propellant charge thermal insulation layer material is mainly made of ablation-resistant polymer materials and inorganic filler materials, and its chemical and physical properties are relatively stable. However, because the propellant-coated charge is generally in a sealed environment, When the ambient temperature changes, the thermal insulation layer will generally produce dimensional changes, and the degree of this dimensional change is affected by factors such as ambient temperature, material formula, coating process, grain shape and size, that is, the thermal expansion coefficient of the thermal insulation layer is different. There is a big difference under different circumstances. Accurate determination of the thermal expansion coefficient of explosives is of great significance for guiding the improvement of explosive formula and charging process and ensuring its safety.

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