Mechanical bonding of solid propellant elements with the case

The relevance of work is caused by the need to increase the efficiency of oil production and the requirements to high-strength joints in places of bonding solid propellant with inner surface of the case. Solid propellant gas-generating devices are widely used in oil production to maintain intra-layer pressure and increase oil production, especially at production of high-viscosity types. At the same time work gas-generating solid propellant defines the effectiveness of oil production. The main aim of the study is to develop a method to bond solid propellant with a case of the gas generating engine that allows expanding operational functionality of solid-propellant engine, increasing manufacturability due to processing steps providing high pull strength between thermal-protective coating and solid propellant. At the same time solid propellant is to be bonded with thermal-protective coating only physically without any structural element e.g. protective liner coating and liner composition.The methods: determination of bonding strength of solid propellant with pull-off method. The results. Shaped lugs on the surface of thermal-protective coating were chosen to be linear semi-dumb-bells that are charge inward facing and made of a material that is chemically compatible with solid propellant. Due to the shaped lugs the mechanical bonding with the propulsion charge is provided. In vitro and under factory conditions the performance capability of the proposed bonding scheme was tested. Some press molds were developed and models of the shaped thermal-protective coating were manufactured. Optimization of the shape was performed during the experiment. Pull-off tests showed that solid propellant were detached from thermal-protective coating profiles and bonding strength with the shaped thermal-protective coating was at a level of solid propellant nominal strength. So the performance capability of the proposed bonding way was confirmed.