面向工业设计的塑料表面铝涂层的结合强度

目的采用电弧喷涂方法在环氧树脂和ABS塑料表面喷涂铝涂层,研究涂层结合强度的影响因素。方法第一组试验是塑料表面喷砂后,喷涂铝涂层;第二组是塑料表面喷砂后,涂覆一层高强度环氧树脂结构胶,再喷涂铝涂层。选择喷涂气体压力、喷涂电流和喷涂距离三因素进行正交试验,采用粘结拉伸法测试结合强度,并用照相法测量铝液和环氧树脂塑料、Q235钢的接触角。结果本试验条件下,二种塑料电弧喷涂铝涂层结合强度的影响因素主次顺序为:空气压力喷涂电流喷涂距离。最优方案是:喷涂气体压力为0.7 MPa,喷涂电流为220 A,喷涂距离为160 mm。未涂覆高强度环氧树脂结构胶的涂层,结合强度最大不超过3 MPa;涂覆高强度环氧树脂结构胶的涂层,结合强度达到近20 MPa。铝液和Q235钢的接触角是45°,和环氧树脂塑料的接触角是135°。结论环氧树脂和ABS塑料表面电弧喷涂铝涂层的结合强度低的主要原因是铝液和它们之间的润湿性差。涂覆高强度环氧树脂结构胶后,喷涂工艺参数对涂层的结合强度影响不明显,结合强度受控于环氧树脂结构胶的粘接作用,使涂层的结合强度显著提高。

The Bonding Strength of the Industrial Design for a Plastic Surface Coating of Aluminum

ABSTRACT:Objective Aluminum coatings were prepared on the surface of epoxy resin and ABS plastics by arc spraying, and the factors affecting the bonding strength of coating were studied. Methods The first group was spraying aluminum coating on the plastic surface after sand blasting. The second group was coating a high-strength epoxy resin structural adhesive on the surface of the plastic after sand blasting, then spraying aluminum coating. Orthogonal experiment was carried out to select the three factors of spraying gas pressure, spraying current and spraying distance. Tensile method was used to test the bond strength, photographic method was used to test the contact angle of epoxy resin and Q235 steel with molten aluminum. Results Under the conditions of this experiment, the main factors affecting the bond strength of aluminum coating were air pressure, spray current and spraying dis-tance. The optimal solution was:spray gas pressure 0. 7 MPa, spray current 220 A, spraying distance 160 mm. For uncoated high-strength epoxy resin structural adhesive coating, the maximum bonding strength was not more than 3 MPa; For coating with high-strength epoxy resin structural adhesive, the bonding strength was close to 20 MPa. The contact angle between the aluminum liquid and the Q235 steel was 45°, and the contact angle of the epoxy resin was 135°. Conclusion Arc sprayed aluminum coating on the surface of epoxy resin and ABS plastic,low coating bond strength was mainly due to poor wettability of molten aluminum between them. After coating the structure of high-strength epoxy resin, the bonding strength of the coating was not significantly affected by the coating process parameters. Bonding strength was controlled by the bonding of epoxy resin structural adhesive, which could sig-nificantly improve the bonding strength of the coating.