对于大型工件进行无损金相分析,或委托单位需要收回金相试样时,常需要制作金相试样的复型。一般制备复型是将塑料纸(约0.1mm厚的醋酸纤维薄膜,即AC纸)覆盖于滴有丙酮的工件或试样的表面上来制作的。由于国产胶片大多采用醋酸片基,所以可利用废醋酸片基的底片来制作金相复型。具体方法如下: For large parts of non-destructive metallographic analysis, or entrusted units need to recover the metallographic sample, often need to make the metallographic sample complex. The general preparation of complex is the plastic paper (about 0.1mm thick cellulose acetate film, that is, AC paper) covered with the dropping of acetone on the surface of the workpiece or specimen made. As most of the domestic film acetate base, so the film can be used to produce acetic acid base film complex type. Specific methods are as follows: