HTPB推进剂湿热老化规律及损伤模式实验

Experimental invetigation for hygrothermal aging law and damage mode of HTPB composite solid propellant

关键词:  复合固体推进剂  老化试验  热老化  扫描电镜分析

Key words:  Composite solid propellant  Agingtest  Heat aging  Scanning electron microscope analysis

摘要:

通过HTPB推进剂湿热老化实验,采用测定单轴定速拉伸条件下标准哑铃形试件声发射(AE)信号的方法,结合扫描电镜(SEM)断面观察结果,对HTPB推进剂的湿热老化规律和损伤模式进行了研究,给出了一个描述湿热老化性能变化规律的三阶段模型。实验研究表明:声发射信号累积计数对时间的导数的大小对应基体开裂、脱湿和宏观断裂三种损伤模式;同时水份破坏粘合剂和氧化剂的界面是导致脱湿关键因素,且水份在推进剂中的浓度与脱湿严重程度呈正相关。

Abstract:

By way of measuring the acoustic emission(AE) signal of HTPB composite solid propellant under condition of uniform speed,combined with the Scanning Electron Microscope(SEM) fracture surface observation,the hygrothermal aging law and damage modes of HTPB composite solid propellant were studied via hygrothermal aging experiment.The three-stage model describing hygrothermal aging law of HTPB composite solid propellant was developed.The results of experiments show that the derivative of AE cumulative counts corresponds to three damage modes,which are binder crack,dewetting and macro-fracture of HTPB composite solid propellant,respectively.The crucial factor causing dewetting is that water breaches the interface between the binder and the oxidizer.Water concentration in HTPB composite solid propellant is positive correlative with the severe degree of the dewetting.