Cars are built from a wide range of materials and component assemblies. Accordingly, defects of automotive parts can be extremely diverse. They might be of purely cosmetic nature (e.g. paint work defects) but can also affect security relevant parts like tires, brakes or electronics.
Also the dimension of the parts to be analyzed can be very different ranging from separated, tiny contaminations to big engine or body components.
The fully automated IR microscope LUMOS II has an excellent accessibility of the sample stage and a large working distance of 30 mm. Samples with a thickness of up to 40 mm can be investigated without any changes of the hardware. Due to these features, many larger samples can be analyzed without sample preparation, saving precious working time.
Here we present the analysis of a fender vent air extractor (“louver”) with a paint defect in form of a barely visible black spot. The image below shows the microscopic image superimposed with the chemical image of the louver surface: On the left side the contamination can be seen, on the right the clean surface is visible.
The chemical image fits perfectly to the visual image and clearly enhances the contrast. Furthermore, it provides information about the concentration gradient of the contaminant. A library search reveals that the contamination is from a black endorsing ink and that the louver is coated with a clear coat finish.
|Learn more in our Application Note AN M114 about the analysis of large car parts.|
Car paints are typically multi layered structures and contain many different materials. As an example, the image below shows an overview with the corresponding spectra of four layers of a paint chip. The color coding of the measurement spots is according to the shown spectra. All layers, including the two white layers can be clearly distinguished by means of their spectra. This spectral information can be used for further evaluations like the identification of the main components, used fillers etc.
|Learn more in the Application Note AN M100 showing the analysis of micro samples using the LUMOS II FTIR microscope.|
The analysis of defects and inclusions on rubber samples like tires can be very challenging since often the defects are microscopically small or show a very low contrast. With FTIR microscopy, even very small contaminations with a very low visual contrast can be visualized and identified.
The image below shows the visual and the chemical image of a contamination on a rubber sample. Besides the contamination that is also evident on the visible image the chemical image shows much more information and reveals contaminations that are invisible to the unaided eye. Of course, it is also possible to identify the chemical nature of the contamination, in this case PTFE and polyamide.
|For more information, read the Application Note AN M136 showing the failure analysis of contaminated rubber part.|
Surface coatings require absolute clean and dry work pieces that are free of remainders like fat, oil or salts. Only small amounts of these surface impurities will result in a poor adherence of the coating substance with all the negative impacts on the product quality.
Small samples and areas can be easily controlled by a microscopic reflection measurement with the LUMOS II. When larger surface areas need to be analyzed a macroscopic analysis by the ALPHA II FTIR spectrometer with an external reflection accessory is more appropriate (see image below).
|For more information, read the Application Note AN M90 showing the detection of surface contaminations on gear wheels with the ALPHA II.|
Modern cars contain a great deal of various plastic parts since plastic is lightweight, easy to process and very durable. Due to the very large amounts, product defects in these automotive parts can happen rather frequently and thus it is important to have the right failure analysis instruments at hand.
This example shows the analysis of black streaks on a polycarbonate sample shown in the microscopic image below. The question is if the streaks are on the surface or embedded in the PC-matrix and what their chemical nature is. By applying the ATR-measurement technique, the IR-microscopic analysis with LUMOS II can be performed without any sample preparation.
By performing a library search on the contamination spectra, it was possible to identify the contamination to be an ink color. With this information, tracking down the cause of the defect is much easier.
|Read the Application Note M101 showing the failure analysis of a contaminated plastic part.|
In the automotive industry front consoles, windshields, seating elements, and car body parts are glued with special automotive adhesives which have led to significant weight savings.
Our example shows the IR microscopic analysis of a piece of hardened adhesive on a PET-foil. The adhesive shows microscopically small white needle like crystals.
The image below displays the chemical image superimposed over the visual image showing the distribution and relative intensity of the defect. The analysis of the spectral information provides further insight in the cause of the defect.
|Read the Application Note M129 showing the analysis of glues in product development and failure analysis.|