高纯铝表面晶面指数对腐蚀孔线长大速度的影响

采用盐酸、硝酸、氢氟酸的混合溶液腐蚀从高纯铝锭上切割出的单晶{100}和{124}表面。统计观察了腐蚀孔的变化过程,回归拟合了腐蚀孔所占面积的变化,并推导了腐蚀孔的线长大速度。结果表明:腐蚀过程中腐蚀孔的线长大速度迅速下降。{124}面的表面能和表面位错应力场均高于{100}面,使点腐蚀初期其腐蚀孔的线长大速度明显大于{100}面。腐蚀后期,{124}面的腐蚀孔必须继续向内部扩展,而{100}面的腐蚀孔则可以只沿表面扩展,因而造成{100}面腐蚀孔的线长大速度大于{124}面。

The Influence of Surface Miller Index of High Purity Aluminum on the Linear Growing Speed of Etching Holes

The solution containing hydrochloric acid, nitric acid and hydrofluoric acid was used to etch the {100} and {124} surface of single crystals which were cut from ingot of high purity aluminum. The evolution of etching holes was observed statistically during the etching. The increase of etching area was analyzed by regression fitting, and the linear growing speed of etching holes was deduced. It is indicated that the growing speed was reduced rapidly during the etching process. The {124} surface exhibited obviously higher linear growing speed than the {100} surface in the initial etching stage because of its higher surface energy and the higher stress field of its surface dislocations. However, the {100} surface showed higher growing speed than the {124} surface in the later etching stage, because the etching holes on {124} surface had to grow towards inside of the sample continuously while those on {100} surface could grow along the sample surface only.