Abrasion and corrosion resistance

SiHcon nitride (see Nitrides) is a key material for stmctural ceramic appHcations in environments of high mechanical and thermal stress such as in vehicular propulsion engines. Properties which make this material uniquely suitable are high mechanical strength at room and elevated temperatures, good oxidation and creep resistance at high temperatures, high thermal shock resistance, exceUent abrasion and corrosion resistance, low density, and, consequently, a low moment of inertia. Additionally, siHcon nitride is made from abundant raw materials. 

Similarly, nylon and fluorocarbon are outstanding dry bearing materials not merely because of their low coefficient of friction but because they offer in addition, a combination of good abrasion and corrosion resistance, fair to good creep resistance, and the ability to absorb abrasive particles. In some instances mechanical plastics are used because of one outstanding property—fluorocarbon for antistick characteristics, for example—but these are not typical. 

The property of elastic recovery of rubbers allows them to be used for many products which are subjected to deformation, whether by tension or compression, and must not be destroyed by such forces. Abrasion and corrosion resistances are often the main properties in choosing an elastomer-based product over alternative products. In the mineral processing industry, abrasion often results from a... 

The segment then undergoes suitable heat treatment to achieve the desired hardness. With the help of HIP technology it is possible to produce highly wear-resistant tool steels (primarily vanadium-alloyed) but also to combine abrasion- and corrosion-resistant properties as required (Cr-, Mo-, V-alloys). HIP technology (see Section 16.4.1) also allows to specifically create materials for different applications. 

The manufacture of the fused cast basalt was pioneered in West Germany about 60 years ago. Fused cast basalt, also known under the registered trademark ABRESIST, is abrasion and corrosion resistant. The material is used worldwide in virtually all industries to protect equipment from the destructive forces of wear. 

Technical data was taken from the Handbook of Abrasion and Corrosion Resistant ABRESiST Linings by Abresist Corp., S.R. 13 North, Ur-bana, Indiana 46990, a subsidiary of Schmelzbasaltwerk, 5461 Kalen-born. West Germany. 

Bayer and Wiedemarm (1981) reported on the mineralogy of zirconium and its uses as precious stones (zircon, phianite, and dje-valithe are all very hard), mineral raw materials, foundry sand, abrasives, and corrosion-resistant metals. Insoluble zirconium silicates have been used in cosmetic creams, powders, and antiperspirants. Zirconium tetrachloride is a white powder that is very moisture-sensitive (Dressier et al. 1983). 

Features Air-curing high gloss and lint retention good chem., abrasion, and corrosion resist., film hardness, and adhesion Properties Milky-wh. liq. dens. 8.80 Ib/gal vise. 200-500 cps bulking value 0.1139 gal/lb (wet) pH 9.8 50% solids Maincote PR-71 [Rohm Haas]... 

Hard anodising is a process where the anodising parameters are changed, leading to a much thicker, harder, abrasion- and corrosion-resistant film. The film formed is dark in colour, so black is the only sensible film colouring. 

Stellite 1 Possess high abrasion and corrosion resistance for applications such as pump sleeves and... 

To obtain the final solid, tough, abrasion-and corrosion-resistant coating, the parts are heated to temperatures in the range 160°C to 210°C depending on the powder. The curing can be done by convection ovens, infrared, a combination of both or by ultraviolet (UV) radiation, which in the case of an automated production line is located at the final stages. Typical coating thickness is around 50-65 p.m. 

The properties of sol-gels that are useful in electroanalysis include abrasion and corrosion resistance, ionic conductivity, optical transparency, and electrochromism. These, along with the ease with which sol-gels can be constructed with variable chemical composition have led to their use in electrocatalysis (116), sensing, and as robust reference electrodes (113). Other applications are summarized in references (113,115). Table 1 in (115) includes an in-depth list of useful sol-gel modified electrodes. 

Tungsten carbide and zirconium diboride electroplates deposited from ion melts by high-temperature electrochemical synthesis can be recommended for an increase in the surface hardness, as well as the wear, abrasive, and corrosion resistance of steel materials. 

Hardcoat anodizing. As the name implies, a hardcoat finish is tough and durable and is used where abrasion and corrosion resistance, as well as surface hardness, are critical factors. Essentially, hardcoating is a sulfuric acid anodizing process, with the electrolyte concentration, temperature, and electric current parameters altered to... 

Fine powder for durable abrasion and corrosion resistant coatings. 

Alloy cast irons are high strength, hard, and abrasion- and corrosion-resistant materials, and are suitable for high-temperature services. Addition of about 5% nickel causes the formation of martensitic... 

Molding of CSM requires some special care in the type of metal due to the acidic nature of CSM even with the presence of an acid acceptor. A hard surface (minimum 45 Rockwell C), abrasion and corrosion resistant and non-porous steel needs to be employed. A hard chrome plate at least 0.1 mm thick is recommended. Stainless steel is a more expensive but more effective alternative. Lower mold temperatures reduce mold fouling and corrosion if economics will allow. Molds need to be cleaned at least weekly with an alkali solution with ultrasonic vibration. 

Ceramic liners have performed well in a wide variety of erosive environments including rotary dryer, cement, coal and ash handling facilities. This material provides a very high degree of both abrasion and corrosion resistance and is highly resistant to thermal shock. It can be cast directly onto a weld mesh support frame welded to the inside walls of a cyclone. Alternatively,... 

Topcoats can be used to protect the surface of coating from wear, abrasion, chemical attack, and environmental deterioration. For example, gold is used as a topcoat for many metallization systems in order to prevent corrosion and allow easy wire-bonding to the film surface. Polymer topcoat materials of acrylics, polyurethanes, epoxies, silicones, and siloxanes are available and are very similar to the coating materials that are used for conformal coatings and basecoats. These topcoats are used to improve abrasion and corrosion resistance of the film. 

Lacquer coating (decorative coating) The topcoat that is used to give abrasion and corrosion resistance, color, and texture to a decorative coating system. The lacquer is typically applied over a reflective aluminum film deposited by vacuum evaporation and may be deposited on a flow-coated basecoat, which creates a smooth surface. See also Basecoat Topcoat. 

---