| Metal/polymer injection molding technology is a gradually emerging molding technology in recent years.This technology with the simple operation,low cost and rapid prototyping of the forming process,which can be various metal alloys(aluminum alloy,magnesium alloy,etc.)directly molded with butylene terephthalate(PBT),polyphenylene sulfide(PPS),Nylon(PA)by injection for strong adhesion of composite high-strength parts.In this paper,the experimental parameters of surface treatment,injection molding and other process parameters are experimentally verified and analyzed through experiments of aluminum(Al)and polyphenylene sulfide(PPS)injection molding composite components.The main contents are as follows:1.A specific experimental mold equipped with cooling systems,heating systems and so on is designed for Al-PPS composite components.In order to control the surface temperature of Al,a mold temperature control system based on PLC system is designed.The surface temperature of Al is monitored in real time by the temperature sensor,and the mold is heated by electric heating element.2.45#,80?,120#and 180#corundum and spraying pressures of 0.1 MPa and 0.3 MPa are used to treat Al surface and injection molding is finished at five different temperatures:30??60?.90?.12?.150?.45#corundum,0.3MPa pressure;120?and 150? mold temperature are taken as the optimal conditions of the surface physical sandblasting Al-PPS composite components molding.The surface roughness of Al treated by different corundum model with 0.3 MPa spray pressure was observed by laser confocal microscope.The effect of surface roughness and roles size on the sandblasting.It was proved that the bonding between A1 surface and PPS in this treatment method was only physical mechanical chimerism.3.The influence of anodic oxidation current density,electrolyte temperature and oxidation time on Al surface adhesion properties was studied by using sulfuric acid/oxalic acid/lactic acid mixed aqueous solution as electrolyte.Experiments show that Al surface treated with the current density lA/dm2,the electrolyte temperature 35?,oxidation time 60min and PPS have maximum binding.The surface of pure Al,A1 without cream anodized,Al with cream anodized were analyzed respectively.The results show that Al surface activity is promoted because of the presence of AlO(OH)and Al(OH)3,indicating the Al surface with cream anodized is both physical chimerism and chemisorption bonding properties.4.y-aminopropyltriethoxysilane(KH550)is taken as an anodized Al-PPS bound intermediate.The effects of KH550 concentration,filming time and filming temperature on the quality of silane films were studied,establish the foundation for the bond of Al-PPS composites.The experiment shows that the optimal ratio of KH550 solution is VKH550:VEtOH:VH2O = 5:75:25,the hydrolysis time is controlled at 0.5h-2h and the film is formed at 175? for 30min,to the optimal silane film.The Al surfaces before and after film formation were observed and analyzed.It was concluded that the formation of Al-O-Si chemical bond is the key to the combination of A1 and KH550.Analysis of the combination of PPS and KH550 is demonstrated that the sulfhydryl group(-SH)in PPS did not react with the amino group(-NH2)in KH550 to generate a new functional group,but the infiltration and fusion of the two substances occurred.The necessity for anodization and KH550 co-treatment of Al surface is illustrated.5.The combination failure of Al and PPS by surface-physical sandblasting is only PPS peeling off from the substrate or not.However,the bonding failure of Al after the anodic oxidation and KH550 film-forming treatment and PPS also includes Al-oxide stripping from Al substrate.The bonding linterface and the cross section were observed and analyzed according to the two different ways to A1 treated and PPS to composite components.The failure causes of composite parts is pointed out to further improve the Al-PPS binding force and evidence of metal/polymer injection molding technology is provided. |
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