Influence of different crosslinking mixtures on the mechanical properties of composite solid rocket propellants based on HTPB

The crosslinking agent is a vital key which affects the mechanical properties of composite solid rocket propellants (CSRPs). Under this scheme, the effect of crosslinking mixtures (CMs) based on trimethylolpropane (TMP) as a triol crosslinker and butanediol (BD) as a chain extender on CSRPs based on hydroxyl-terminated polybutadiene was investigated. A series of 27 propellant compositions was formulated to study the mechanical properties of the prepared CSRPs. The effect of changing the weight ratio of TMP to BD in the CM was studied. In addition, the influence of increasing the percentage of CM (from 0% to 0.5%) in the prepared samples was investigated. Also, the effect of the CM on CSRPs containing different curing ratio of NCO/OH = 0.7, 0.75, and 0.8 was studied to generate the largest possible strain-ability with high strength over different levels of curing conditions. The mechanical characteristics (tensile strength and strain) of the prepared CSRPs have been measured and plotted versus CM content, NCO/OH and TMP:BD ratio. Generally, the addition of CM leads to a remarkable enhancement in the propellant mechanical properties. Samples containing TMP:BD (2:1) provide the highest strength while samples containing TMP:BD (1:2) show the highest strain over all the NCO/OH ratios. Formulations with TMP:BD (1:1) give high strength with moderate strain. Variation in CM content has a remarkable influence on the mechanical properties of CSRPs. A wide range of tensile strength and strain were obtained from this study to offer variety of results suitable for different applications in the CSRPs technology.

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Synthesis of HTPB using a semi-batch method

Materiały Wysokoenergetyczne / High Energy Materials ◽

10.22211/matwys/0115e ◽

2020 ◽

pp. 192-202

Author(s):

Michał Chmielarek ◽

Wincenty Skupiński ◽

Zdzisław Wieczorek

Keyword(s):

Mechanical Properties ◽

Hydrogen Peroxide ◽

Synthesis Method ◽

Batch Method ◽

Synthesis Conditions ◽

Rocket Propellants ◽

Wide Range ◽

Military Applications ◽

Solid Rocket ◽

Solid Rocket Propellants

Hydroxyl-terminated polybutadiene is widely used in industry for both civil and military applications. In munitions, HTPB is mostly used as a binder for heterogenic rocket propellants and as a component of plastic bonded explosives, as well as a phlegmatizer in explosives sensitive to friction and impact. The wide range of HTPB applications results from the good mechanical properties of HTPB-based polyurethanes, in particular at temperatures down to –40 °C. A synthesis method for HTPB, different from the commonly used semi-batch and continuous methods, is presented. The effect of parameters including reaction temperature, 1,3-butadiene pressure and hydrogen peroxide concentration on the properties of the obtained polymer is determined. The synthesis conditions enabling new HTPB species to be obtained, which meet the requirements for binders used in solid rocket propellants, are specified.

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An assessment into mechanical properties and microstructural behavior of TIG welded Ti-6Al-4V titanium alloy

Grey Systems Theory and Application ◽

10.1108/gs-11-2019-0052 ◽

2020 ◽

Vol 10 (3) ◽

pp. 281-292 ◽

Cited By ~ 1

Author(s):

Saurabh Dewangan ◽

Suraj Kumar Mohapatra ◽

Abhishek Sharma

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Weight Ratio ◽

High Strength ◽

Hardness Test ◽

Content Type ◽

Ti Alloys ◽

Microstructure And Mechanical Properties ◽

Grade 5 ◽

Selection Of

PurposeTitanium (Ti) alloys are in high demand in manufacturing industries all over the world. The property like high strength to weight ratio makes Ti alloys highly recommended for aerospace industries. Ti alloys possess good weldability, and therefore, they were extensively investigated with regard to strength and metallurgical properties of welded joint. This study aims to deal with the analysis of strength and microstructural changes in Ti-6Al-4V (Grade 5) alloy after tungsten inert gas (TIG) welding.Design/methodology/approachTwo pair of Ti alloy plates were welded in two different voltages, i.e. 24 and 28 V, with keeping the current constant, i.e. 80 A It was a random selection of current and voltage values to check the performance of welded material. Both the welded plates were undergone through some mechanical property analysis like impact test, tensile test and hardness test. In addition, the microstructure of the welded joints was also analyzed.FindingsIt was found that hardness and tensile properties gets improved with an increment in voltage, but this effect was reverse for impact toughness. A good corroboration between microstructure and mechanical properties, such as tensile strength, hardness and toughness, was reported in this work. Heat distribution in both the welded plates was simulated through ANSYS software to check the temperature contour in the plates.Originality/valueA good corroboration between microstructure and mechanical properties, such as tensile strength, hardness and toughness, was reported in this study.

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