The quality assurance of functional and decorative finishes in automotive construction calls for precision testing of coating thicknesses and material properties.
In the automotive industry paint coatings are used as protection from corrosion and external damage. These lacquers are exposed to environmental influences such as extreme temperature fluctuations or moisture and salt. In addition, automotive coatings must exhibit a certain toughness to make them resistant to stone chips and scratches, for example in car washes. This requires the right balances between hardness and elasticity.
In the automotive industry, a great deal of effort goes into reducing vehicle weight by using lighter components. An example is the use of SAM (sprayable acoustic material) coatings in vehicle interiors. These locally applied insulation layers replace the larger and heavier soundproofing mats previously used. However, in order to meet the targets for sound protection, weight, clearance and cost, the thickness of these coatings must be carefully monitored.
In the automotive industry, the plungers used inside the solenoid valves of automatic transmission gearboxes must fit smoothly into their through-holes to an accuracy of just a few µm, in order to prevent oscillations that would lead to jamming or canting. To meet these tight tolerance limits, the plungers must be coated very evenly, which requires strict quality control.
Automotive cylinders are subject to extreme mechanical wear. A way of protecting aluminum cylinders is to plate the contact surfaces with Nikasil®, a hard coating technology used to improve the tribological characteristics of the cylinder parts and to optimize the heat transfer. It is often used for high-end engine components of premium car brands and in motor sports.
In order to reduce emissions in combustion engines without sacrificing performance, manufacturers are continually working to improve the ability of the moving parts (e.g. camshafts, piston rings and gears) to resist abrasion and reduce friction. Coating them with DLC (diamond-like carbon) is just such an optimization. DLC coatings are not only very hard but also feature a certain toughness – which are two of the critical parameters that must be monitored during the coating process.
In the automotive industry weight reduction – and the associated fuel savings – are top priority, which is why lightweight materials such as aluminum are used. In order to withstand mechanical stresses, however, these softer components must be made wear resistant. For this reason, hardcoat (Type III) anodization is becoming ever more common.
For automotive manufacturers, it is of increasing importance to control the quality of the paint processes in order to ensure effective corrosion protection while reducing costs. Especially in EDP (electrophoretic deposition) processes, this requires adherence to tight tolerance limits, which in turn, requires careful monitoring. But the measurement task itself should also be fast and cost-effective; the instrument must be able to measure lacquer atop various base materials (mainly galvanized steel or aluminum) without refitting or recalibration.
In the automotive industry, the anti-rust warranty has become an important hallmark of car quality. Particularly in hard-to-reach areas such as the cross beams and pillars of the steel car body, specified tolerances for CDP coating thicknesses must be ensured, because in these areas, corrosion can proceed long undetected.
For a variety of reasons, assessing the quality of paint coatings on car bodies is increasing in importance. Narrow tolerance limits and strong demand for smooth finishes require precise measurements of the coating thickness according to clearly defined testing procedures. In addition, the measurement results should provide clues for potential process optimizations. Therefore, consistent inspection procedures – regardless of who is doing the measuring – are also essential.
Whether rolling, pressing, drawing or stamping, chipless coldforming of sheet metals simply does not work without lubrication. Especially in the automotive industry, the need for ever reduced air resistance and to meet ever more challenging design requirements continues to grow. The result of the forming process depends largely on proper lubrication, which is used, for example, to reduce friction between the forming tool and the workpiece to prevent them from sticking together – a condition that can exert negative impacts on both the workpiece and the expensive forming dies used. The thickness of the lubricant film must therefore meet specifications within a narrow tolerance range.