腔内约束电热爆喷涂涂层的形成

在内径为7 mm的聚乙烯爆炸腔进行钼丝的电热爆喷涂试验,用扫描电镜观察涂层的表面和截面形貌、涂层厚度,分析涂层与基体的结合情况.结果表明,爆炸腔内钼丝的爆炸产物在基体上会形成一个喷涂圆面,由中心涂层区和外围粘结层组成.中心涂层区在喷涂距离5～8 mm时,所得涂层致密、厚度均匀,与基体结合良好,局部界面附近存在元素扩散现象;外围粘结层随喷涂距离的增大而消失.大面积喷涂层可由单个喷涂圆面的合理搭接来形成,通过多次喷涂可增加涂层的厚度.

Coating formation of electro-thermal explosion spray in constrained capillary tube

The polyethylene capillary tube with 7 mm inner diameter was used for the experiment of electrical spraying of Mo wire.The coating topography,the shape and thickness of cross section,and the bonding between coating and substrate were analyzed.The results shows that explosion products of Mo wire in a constrained capillary tube forms a spraying spot,which consists of central coating and outer adhesive layer.When the spraying distance is 5~8 mm,the central coating is compact and uniform,bonding between coating and substrate is good,the diffusion occurs in the interface between them.While with the spraying distance increasing,the outer adhesive layer vanishes.Large coating could be formed by overlapping single spraying spot reasonably,and thick coating could be obtained by spraying several times.