小径厚比金属波纹管无模成形工艺

Dieless forming process of metal bellows with small radius-to-thickness ratio

传统成形工艺制备的波纹管存在过度减薄及性能恶化等问题,限制了其在航空航天领域的应用,利用局部加热和轴向压缩诱导管坯发生轴向屈曲从而成形的无模成形工艺制备波纹管。为了利用无模成形工艺获得径厚比较小、波纹均匀、综合性能良好的波纹管,采用试验与有限元模拟相结合的方法,对加热温度、变形区宽度、压缩比对成形载荷、波纹管波纹形状、波峰高度、波峰间距以及波峰厚度的影响规律进行了研究。研究结果表明:随着加热温度的升高,波纹管的成形载荷显著降低;随着变形区宽度的增加,波峰高度和波峰间距呈增加趋势,而波峰厚度呈减小趋势;随着压缩比的增加,波峰高度呈增加趋势,波峰间距呈减小趋势。

The excessive thinning and performance deterioration of bellows prepared by the traditional forming process limit the application of bellows in the aerospace field.Therefore,the bellows was fabricated by the dieless forming process that induced the axial buckling of tube blank by local heating and axial compression.Furthermore,in order to obtain the bellows with small radius-to-thickness ratio,uniform corrugation and good comprehensive performance by using dieless forming process,the influence laws of heating temperature,deformation zone width and compression ratio on forming load,corrugation shape of bellows,peak height,peak spacing and peak thickness were studied by combining experiment and finite element simulation.The research results show that with the increasing of heating temperature,the forming load of bellows decreases significantly.As the width of the deformation zone increaseing,the peak height and peak spacing tend to increase,while the peak thickness tends to decrease.With the increasing of compression ratio,the peak height tends to increase,and the peak spacing shows a decreasing trend.