电铸-电解组合法加工双向喇叭孔阵列

为解决双向喇叭形金属微小孔阵列的高效低成本制造难题,提出了一种基于镂空型惰性金属模板的、由电铸加工与掩模电解加工步骤串接而成的组合式加工方法。基于建立的数学模型,在证实该组合加工可行性的基础上,进一步仿真分析与试验研究了惰性金属模板结构参数对被加工孔阵列几何结构形状的影响规律,并进行了参数优选,数值分析与试验结果基本一致。研究结果表明:被加工孔阵列的几何特征参数严重受惰性金属模板结构参数的影响;采用大厚度、大于90°开口角的惰性金属模板有利于获得最小孔径更小且出入口廓形对称性更好的双向喇叭形孔;模板筋宽越小,越易于实现大孔深、高对称性的双向喇叭孔;模板孔径越大,喇叭孔金属层的极限厚度越大,但出入口廓形的对称性越差。此外,在小筋宽、90°开口角的惰性金属模板上更易电解加工生成""形喇叭孔。基于优化的惰性金属模板,能电铸-电解组合加工出出入口廓形对称性好的、最小孔径比被复制模板孔小的、网片厚度大且表面光滑的双向喇叭形金属微小孔阵列,其进出口的对称度、孔径偏差与出口相对于最小孔径的扩口率等分别为88.8%、9.7%和110.1%。

Fabrication of Through Hole Array with Double Tapered Openings Using Electroforming and Mask Electrochemical Micromachining

Basing on an inert perforation metal plate, a hybrid electrochemical fabrication approach combining electroforming and mask electrochemical micromachining is proposed to manufacture efficiently metal through hole arrays with double tapered openings. The feasibility of this approach is first investigated numerically according to the developed numerical models, and then the effect of pattern parameters of the inert metal plate used in the hybrid fabrication on the geometrical characteristics of the through hole array to be machined is numerically analyzed. Furthermore, optimal pattern parameters are determined. Experimental results agree with numerical analysis on the whole. Research results show that, the geometrical characteristics of the shaped through hole array are to a great extent dependent on the pattern parameters of the inert metal plate used. Smaller through holes with better opening contour symmetry can be achieved if a thicker inert metal plate with a bigger mask wall angle is used. With the reduction of the rib-width of the inter metal perforation plate, the depth, minimum diameter and opening contour symmetry of the machined hole become better. With the increase of perforation of the inert plate, the limiting thickness of the machined through hole plate becomes bigger, but the minimum diameter gets smaller and the opening contour symmetry worse. In addition, inward horned-shaped contour in one or two openings can be easily shaped electrochemically when the inert perforation metal plate with a narrow rib and a small mask wall angle is utilized. With a diameter deviation of 9.7% between the inlet and outlet opening, and an expanding rate of 110.1%, a favorable through hole array can be fabricated with good opening contour symmetry (88.8%), fine holes with diameters smaller than the plate perforation copied, and smooth surfaces by using the hybrid electrochemical fabrication method.