Papers by Keyword: Nano Coating

Abstract: Fire hazards in buildings pose a critical challenge, necessitating effective fire protection measures. This study evaluates the potential of nano-calcium hydroxide (NCH) as an additive in fire-resistant paints. Laboratory experiments were conducted following the ASTM E119 standard, testing paint formulations with 1% and 3% NCH. Thermal resistance, protective performance, and economic feasibility were analyzed. Results indicate that NCH-modified paints significantly enhance fire resistance compared to conventional coatings, offering a promising solution for improved fire protection in construction.

Abstract: As the demand of the automotive and aerospace industries for lightweight and cost effective materials increases, it is necessary to combine different materials with respect to their lightweight and functional properties. The combination of polymer-steel-sandwich composites - which consist of a polymer core structure (transferring shear loads) and two metal face-layers (absorbing tensile and compression loads occurring at bending) - suite the need of minimizing weight per area under bending loads. The reduction of process steps can be achieved by connecting the face layers and core in-situ via an in-mold assembly process using variothermal processing. The injection mold hereby is heated near the melt temperature of the polymer with a variothermal water processing unit. Via contact heating inserted steel blanks are heated to the same temperature as the mold. This process enables the combination of the metal surface with the polymer core by infiltrating the micro or nano scale structure, which is generated by laser structuring or nano coating. Through the increased mold/blank surface temperature induced via variothermal heating the melt viscosity is lowered. This decreasing viscosity of the polymer melt hereby enables a higher degree of infiltration of the laser structured and nano coated blanks. This improved infiltration behavior is a key factor for the adhesion of the sandwich components and beneficial for the composites strength. Within this work two steel blanks are inserted into the mold to manufacture sandwich structures with steel face layers and a polymer (here: polylactidacid; PLA) core. As these sandwich composites are prone to bending failure, the 4-point-bending test is used to characterize the mechanical properties of this hybrid structure. The two surface treatments will also be compared concerning their mechanical interface properties with a shear edge test. The additional reduction on the polymer melt viscosity by means of gas inducing with chemical blowing agent is investigated on the laser structured surfaces only. To investigate the influence of the polymers melts viscosity on the bonding properties chemical blowing agent is added for some blanks.

Abstract: a low surface energy coating with a long chain fluorine siloxane is prepared, and the performance in anti-freezing adhesive is studied. It is determined that the optimum proportion of (Heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane (FAS) and SiO₂ nanopowder are 1.1% and 1.6%,respectively. the times of coating bear pendulum impact is least in this proportion. the conclusion is that bionic superhydrophobic coating plays a certain guiding role on solving material surface frozen sticky problem.

Abstract: Surface decarburization is one of important issues in spring steel production. The novel decarbonization-resistant nano-coating has been successfully fabricated, by using a low-cost, and easily accessible bauxite minerals and other additional components, including magnesia, silicon carbide，glass powder and agglomerant, which is used to prevent spring steels from being decarburized during the hot-rolling process. The microstructure of the protective nano-coating is observed by means of X-ray diffraction, TG-DTA, metalloscope and so on. It is found that even if some glass ceramic exists within the coating in the initial lower temperature (950°C~1000°C) the decarbonization-preventing coating still presents decarburization resistance up to 72.2%. Furthermore, the protective ration reaches to 100% when the heating temperature rises to range (1050°C~1100°C). The excellent decarbonization preventing properties are attributed to the formation of glass ceramic and pleonaste, which hinders the second interdiffusion of oxygen and carbon.

Abstract: Membrane surface modification is the important method to decrease membrane fouling. The hydrophilic modification of ceramic membrane with nano-sized inorganic coating is prepared by the wet chemical methods. The thin nano coating is not a separating top layer but distributes uniformly on the surface of the membrane pore wall. The coating does not change the structure of the membrane pores. Therefore, water flows on not the pore wall but the nano coating surface. The results show that the water flux of the modified membrane is higher than that of the unmodified membrane despite that the mean pore size of the modified membrane decreases. The “boundary slip” is used to explain this special phenomenon. What generates the slippage The slippage is relative with the molecular layer adhered tightly on the hydrophilic pore wall, the roughness and the surface charge of the nano coating, the interaction between the ions in water and the nano coating, et al.

Abstract: Membrane surface modification is the important method to decrease membrane fouling. Recent efforts have been made to develop the hydrophilic modified ceramic membrane with nano-sized inorganic coating in our research group. In the modified membrane, the nano coating does not form a separating layer, just distributes uniformly on the surface of the membrane pore wall. It results in that: (1) if the feed is water, the water flux of the modified membrane is higher than that of the unmodified one despite the fact that the mean membrane pore size decreases after the modification; (2) if the feed is oily emulsion, the steady flux is obtained in a short time and keeps in the following time. The flux is far higher than that of the unmodified one because the hydrophilic nano coating prevents the cake from forming on the membrane surface. The nano-sized metal oxide modification application in the membrane technology not only expands the newly research area of the membrane technology but also makes the modified ceramic membrane have a good perspective application in the industry. This paper will introduce the development of the modified membrane with nano inorganic coating and give a clear future research direction.

Abstract: Nano-coatings were prepared by sol-gel process using titanium butoxide and cerium salt as precurors. The substrates were coated by dip-draw method. The structure of nano-coating was characterized by X-ray diffraction (XRD). The degradation activities of nano-coatings were evaluated by testing their efficiency in removing acetone and decane. Results show that the conversion rate of decane and acetone by TiO2 nano coating doped 1.0 wt % Ce was much higher than that of common unmodified TiO2 nano coating.

Abstract: As more and more special refractory materials apply to laser processing technology, many processing problems have highlighted, this article studies on how to improve the laser absorption rate in the processing of work piece, and proposes the method of nanometers particles attached to improve absorption efficiency of laser materials before the laser processes smooth surface work piece materials, to analysis and forecast the theoretical effects[1]. Through the laser processing energy loss analysis and research, we can identify the major loss of laser processing means. Combined with the most commonly used laser processing smooth work piece surface pretreatment method deficiencies and some characteristics of nano-coating, nano-coating will focus on the process of laser processing to further improve the efficiency of heat absorption to provide a new way of settlement[2].

Abstract: Ceramic composite armour in general utilises a front layer of dense ceramic, typically backed by a second layer of metal. Thereby creating a sharp interface that is the weakest link within the material system and would result in cracking of the ceramic prematurely and hence not able to provide the requisite protection. One promising possibility has been found is the use of functionally gradient materials as armour materials. In such materials, the high hardness of ceramics is combined with the ductility of metals. Laboratory scale experiments were being performed to exhibit the potential of this material in terms of physical and mechanical properties. A comparison was made with the current ceramic armour system and it was found that the new material system had better ballistic properties.

Abstract: Modern trends in metal cutting, high speed/feed machining, dry cutting and hard cutting set more demanding characteristics for cutting tool materials. The exposed parts of the cutting edges must be protected against the severe loading conditions and wear. The most significant coatings methods for cutting tools are PVD and CVD/MTCVD today. The choice of the right substrate or the right protective coating in the specific machining operation can have serious impact on machining productivity and economy. In many cases the deposition of the cutting tool with a hard coating increases considerably its cutting performance and tool life. The coating protects the tool against abrasion, adhesion, diffusion, formation of comb cracks and other wear phenomena.