The solid-state phase transitions in ammonium nitrate (NH4NO 3) and potassium nitrate (KNO3) solid solutions and the equilibrium NH4NO3-KNO3 (AN-KN) phase diagram have been determined. The phase transitions and phase diagram were determined by using the differential scanning calorimetry (DSC) and high temperature X-ray diffractometry. Samples of several different compositions were made for these analyses in a special “Dry Room” with very low humidity. In the X-ray diffraction experiments, the samples were heated on Pt-Rh strip and LaB6 or Si was added for internal calibration. Equilibrium phase diagram was also calculated by using the “FactSage” computer program. A single (AN III) phase region without any phase transitions between 293 to 373 K was observed for compositions between 5 to 25wt% KNO3 in NH4NO3 that is critical for air bag gas generators. The higher temperature KNO3 (KN I) phase has a wide stability range, from 100%KNO3 to 20%KNO3 solution. There is one eutectic, two eutectoids, and two peritectoids in this phase diagram. Two newly discovered solid-state phases were found in the mid-composition range of AN-KN solid solutions. Details of phase equilibria and lattice expansions during heating have been determined. Phase diagram calculations show a reasonable match of the phase boundaries. The total vapor pressures as well as the average molecular weights of pure ammonium nitrate and 16% KNO3 solid solution were measured at various temperatures by the torsion-Knudsen effusion method. The partial pressures of NH4NO3 (PNH4NO 3), NH3 (PNH3), and HNO3 (PHNO 3) have also been determined.
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机译：硝酸铵（NH 4 NO 3 ）和硝酸钾（KNO 3 ）固溶体中的固相转变以及平衡NH <确定了sub> 4 NO 3 -KNO 3 （AN-KN）相图。通过使用差示扫描量热法（DSC）和高温X射线衍射法确定相变和相图。在湿度非常低的特殊“ 干燥室”中，制备了几种不同成分的样品进行这些分析。在X射线衍射实验中，将样品在Pt-Rh试纸上加热，并添加LaB6或Si进行内部校准。还使用“ FactSage”计算机程序来计算平衡相图。在NH 4 NO 3中含有5至25wt％的KNO 3 之间的组成时，观察到一个在293至373 K之间没有任何相变的单一（AN III）相区域对安全气囊气体发生器至关重要。较高温度的KNO 3 （KN I）相具有很宽的稳定性范围，从100％KNO 3 到20％KNO 3 溶液。在此相图中，有一个共晶的，两个共析的和两个共晶的。在AN-KN固溶体的中间组成范围内发现了两个新发现的固态相。已经确定了加热过程中相平衡和晶格膨胀的细节。相图计算显示出相边界的合理匹配。通过扭转-努森渗流法在不同温度下测量了纯硝酸铵和16％KNO 3 固溶体的总蒸气压以及平均分子量。 NH 4 NO 3 （PNH 4 NO 3 ），NH 3 （PNH 3 ）和HNO 3 （PHNO 3 ）也已确定。
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