Advances in surface coating technology

1978 ◽  
Vol 11 (3) ◽  
pp. 163-165
2011 ◽  
Vol 412 ◽  
pp. 410-414
Author(s):  
Yun Wang ◽  
Ji Kang Yan ◽  
Guo You Gan ◽  
Jing Hong Du ◽  
Jian Hong Yi

In order to improve the dispersion of TiO2, use the surface coating technology to form the aluminium ion film on the surface of TiO2, so as to achieve the aim of modification. Use the aqueous solution sedimentary drying method to make the alumina coating experiment under as certain technical condition, use the test like the scanning electron microscopy and transmission electron microscope, etc to analyze the coating powder’s dispersive and coating situation. The paper started from the angle of ion sedimentary reaction equilibrium, made the thermodynamics analysis on the coating on the surface of TiO2 and got the [Al]T-pH relationship diagram about the aluminium ion, and then confirm the PH extent for the aluminium ion’s completed sedimentation. The result indicated that, when the PH value reached from 8 to 12, the aluminium ion would completely precipitate.


2015 ◽  
Vol 766-767 ◽  
pp. 606-611 ◽  
Author(s):  
T. Arunkumar ◽  
S. Ramachandran

Polyurea coatings are very reactive and fast curing even at very low temperatures with exceptional mechanical properties, chemical resistance and durability. Polyurea spray coating technology is used to overcome the initial problems in surface coating such as substrate wetting,mixing and surface finish. The study deals with the analysis of morphology and tensile properties of polyurea coating. The polyurea sample is characterized by using SEM, FTIR and XRD in addition to EDAX to determine the microstructure and chemical composition. Finally Tensile Test was carried out to examine the ultimate tensile strength and young’s modulus of Polyurea using UTM.


Surface coating has evolved with time, tracking the demands of the processing industry. This research activity, studies the significance of powder coatings in the evolution of existing conventional surface coating technology for their practical applications in the field of metal coating, particularly office and home appliances. The first objective of this work involves a systematic comparison between polymer powder coatings with liquid-based coatings. In the second objective, a comparison between the polymer coatings with additive filled powder coating was performed. Various conventional substrates (such as copper, aluminium, galvanized iron, brass, cement plank, wood block) were used for this study. The materials were first dry scuffed and then dipped in 3 in 1 chemical (zinc phosphate chemical and magnesium phosphate) for the primer coat. The prepared substrates were surface coated with liquid paint (on one side of the panel) using spray gun and powder paint (on another side of panel) using electrostatic spraying. The coated panels are then subjected to various standard (ISO) characterization techniques such as Scratch hardness test, Flexibility test, Thickness test, Adhesion test, Impact resistance test etc to analyze the effectiveness of the coatings applied. The quantitative and qualitative results thus obtained using powder coatings were promising (e.g: As the load progressively kept increasing i.e. 1000-2000 gm, mild scratches were noticeable on liquid coated substrates whereas powder coated metal panels have shown a greater resistance to scratch damage) as the test values determined high strength quality and durability (in-line with the standards) in comparison with liquid coatings. Also, the doping of additive (graphene) in small quantity has improved characteristics and qualities of the powder coated materials (e.g: graphene based powder coating has endured scratch hardness test beyond 2500 gms load force compared to simple powder coating). The findings of the current research study has confirmed the advantage of the powder coating technology and also deliberated the effect of fine powder flow ability. The important future prospects of this research work is that., powder coatings will stand on the threshold of exciting breakthroughs thus opening new frontiers by being able to coat thick steel components and even non-metal substrates. Also, the recent advances in powder coating technology with anticorrosive additives will result in bonded metallic coatings that deliver a unique, quality appearance.


2011 ◽  
Vol 418-420 ◽  
pp. 851-855
Author(s):  
Jin Wei Yu

Now the protection method for PCB welding board, widely used coating technology is ENIG , but in use course found that the coating will appear “black mat” that is fatal flaw in the welding process, in order to solve this problem, the engineers and technicians have taken various methods of strict control parameter, despite the improvement, but has not eradicated “black mat” this hidden trouble .Electroless palladium layer is introduced in ENEPIG surface coating new technology, from the reaction mechanism stopped nickel-plate oxidation, in the process of immersion gold blocked off nickel-plate contacted with Immersion gold solution, and effectively prevent pervasion and migration of nickel , thus effectively inhibit oxidation of nickel surface, prevent the “black mat” flaw . Not only have given the technology production process and parameter control, but also have microcosmic appearance and diffusibility analysis for the products by using SEM and EDS , the results showed that palladium layer is non-crystalline film with good uniformity of coating thickness, and did not find pervasion of nickel on gold surface, successfully achieve ENEPIG PCB mass production, replace ENIG technology .


2011 ◽  
Vol 418-420 ◽  
pp. 777-780
Author(s):  
Jin Wei Yu

Electroless palladium are introduced to ENEPIG surface coating technology, from reaction principle to prevent oxidation of nickel-plated, but the process conditions and parameters of practical application are whether or not mass-produce condition , need using a series of reliability experiments to validate it , to reduce risk coefficient of mass-produce , to satisfy customer requirement. Therefore, put forward a package of experimental programs, including experiment projects, experiment methods, instrument and equipment for test, evaluate requirement, test result and analysis etc , especially using TEM have in-depth analysis for interface alloy compound of ENEPIG coating player with SAC305 , systematically verified ENEPIG production technology are mature and reliable, it is considered to be versatile surface coating technology, and particularly suitable for application in gold bonding and surface mount hybrid assembly board which are high connecting reliability product, completely replace the current ENIG technology.


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