固化炉成型复合材料孔隙率超声检测方法研究

Ultrasonic Testing Study for Autoclave Cured Composite Material Porosity

中航通飞研发的AG300型飞机是以碳纤维复合材料为主材料的新型公务机,该机型采用更为高效的新型复材制作工艺,但其同样存在孔隙率较大的问题。孔隙率的大小及分布特征直接影响到结构件特别是应力集中的关重件的力学性能,故急需对其孔隙率进行可靠和准确的无损评价。提出一种通过喷涂溶剂的复合材料孔隙率试块制备方法,利用超声衰减法和金相分析法对前人的经验公式进行标定,将标定后的经验公式计算出来的孔隙率与经过金相分析得到的孔隙率结果进行比对,画出拟合曲线,结果表明误差不大于0.4%,验证了该经验公式应用于工程实践的可行性。

AVIC General＇s self-developed all-composite fuselage AG300 aircraft is a new kind of business jet based on carbon fiber composite material, using the curing oven molding, which is high-efficiency than conventional autoclave molding, but the porosity is bigger than that of the traditional process. The size and distribution of porosity directly affects the mechanical properties of structure, particularly vital member with stress concentration, so the need is urgent for reliable and accurate nondestructive evaluation of their porosity. We introduce a kind of preparation method for composite material porosity block by spraying solvent, using the ultrasonic attenuation method and metallographic analysis to carry out the calibration of the predecess or experical formula. We compare the porosities from calculated empirical formula and metal- lographic analysis, and draw the fitting curve. The error is not more than 0.4%, which verifies application possibility of this empirical formula in the engineering practice.