内孔电弧热喷涂装置及涂层结构的研究

Study on Inner Hole Arc Spraying Device and Coating Structure

为了实现给铝制发动机缸体内壁喷涂铁基耐磨涂层,设计并制造一种新型的适合直径80 mm及以上内孔的电弧喷涂装置。利用所设计的喷涂装置,采用08Mn2Si作为喷涂丝材,分别选用不同的电流和不同的喷涂距离进行喷涂,通过对涂层微观组织比较分析得出,采用电流70 A和喷涂距离70 mm时,完全可以满足对直径80 mm及以上内孔的喷涂,进而对涂层结构研究时发现,在涂层中具有大量铁基氧化物,涂层结合界面上没有大的氧化物、孔隙及夹杂,涂层结合强度高且涂层组织结构由外部到内部基本一致。

In order to realize spraying iron-based coating on the aluminum engine cylinder inner wall, a new kind of arc spraying device was designed and manufactured suitablly for the inner hole of which diameter was 80 mm or above. Using08Mn2Si as spraying wires, coating was sprayed in different currents and different spraying distances with the arc spraying device designed. Through a comparative analysis on coating microstructure, with current 70 A and spraying distance 70 mm, it completely fits the inner hole of which diameter is 80 mm or above. And then, a large number of iron-based oxide in the coating structure is found, while the coating interface has none of big oxide, porosity or inclusion. The microstructure of coating from external to internal is the same and takes high adhesive strength.