Preliminary Study On The Combustion Performance Of Al-based Alloy Powder And Research On Reaction Of Al-H₂O Via Electrochemical Technology

In order to improve the combustion performance of Al powder in solid propellantsystem, the influence of adding Mg and other metal additives on the combustionperformance of Al alloy powder was studied.The phase and combustion performance of Al-Mg alloy powder prepared bymechanical milling and gas sputtering have been analysed by XRD, SEM and DTA. Theresults show that the alloying degree of Mg in gas sputtering powder is more intensive andthe phase of which contains Al₃Mg₂and Al solid solution. The ignition performance of gassputtering powder is better and the exothermic quantity is higer. The componet of millingpowder is Al solid solution and unalloyed Mg particle. The two substance burnedseparately during heating process，which is poorer than gas sputterting powder.By analysising the phase and combustion performance of different content of Mgand other metal additives to alloy powder, it can conclude that the mainly phase of Al-Mgalloy turns from α-phase (Al solid solution into β-phase(Al₃Mg₂and γ-phase(Al₁₂Mg₁₇ withthe increase of Mg content. And the combustion performance of which is better. The primary ignitiontemperature of alloy powder is decreased200℃by the additon of Ga、Sn、In、Sb. The exothermicquantity is improved by adding Zn.In order to facilitate evaluate the combustion performance of Al powder in the water ramjet system,4different sized Al powder(50nm,2μm,13μm and29μm were studied from the perspective ofelectrochemical technology. A characterization system of using electrochemical parameters(corrosionpotential Ecorr, corrosion current density Icorrand corrosion potential temperature coefficient Ecorrwas initially established by measuring potentiodynamic polarization curves of Al-H₂O reaction indifferent temperatures. The results show that the corrosion potential Ecorr decreases with the reductionof particle size and the rate of decrease is relatively significant when the particle size is less than2μm.The combustion efficiency of50nm-Al powder in Al-H₂O system is90.6%, which is much higher than2μm-Al powder,which is66.7%, under25℃.