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Automotive Quality Control (AQC^TM)
For manufacturing companies, defining contamination is relatively straight-forward. Contamination is a particle, or debris, which is not inherent to the final assembly, component, or fluid being analyzed. Unfortunately, removing and controlling contamination, is not as easy as DEFINING it!

The first step towards achieving Quality Control is reliably identifying the individual particles as well as accurately sizing them. Various methods exist, but lack the required sensitivity, accuracy, and precision to maintain adequate control over a process.




Comparison of different contamination detection methods and the information they provide.  Both the Particle Size & Quantity and Identification capabilities are represented.

Analysis of particulate materials by an automated electron-beam instrument is a powerful and practical technique for understanding particle distributions. With its superior magnification range, depth of field, and powerful contrast mechanisms it enjoys many performance advantages relative to the optical microscope for dimensional analysis of particles from the millimeter to the sub-micron range. When equipped with x-ray analysis capabilities, it offers rapid and unambiguous classification of particles by elemental composition. Optimization of the integrated instrument to make full use of its ability to dynamically position the electron beam results in substantial improvements in analytical precision and speed over a simple camera-like SEM interface.

OEMs and vendors throughout the global automotive industry are pushing the envelope of quality control, seeking new ways to improve quality yields and reduce warranty costs. In their quest for Six Sigma quality performance, and higher standards of critical cleanliness, they are focusing greater attention on microscopic particle analysis as part of factory-floor QC operations.

Currently, the AQC^TM is revolutionizing the way particles are being detected and analyzed by providing manufacturers with Industrialized Electron Beam Analyzers capable of evaluating the Size, Shape, and Elemental Composition of all particles present in a sample.  These analyzers rely on the trade marked and patented designs of modular electronics, vacuum functionality, consumable electron emitter hardware, environmental shielding, and maintenance free Elemental Composition detectors. Aspex’s Industrialized-By-Design™ product line offers robust particle analysis solutions for manufacturers in need of easy-to-use equipment for contamination monitoring down to the single particle level with the ability to position the equipment anywhere in the process – lab or manufacturing floor.

In response to these trends, ASPEX has developed the industry's only totally integrated solution for the automated detection, identification, and characterization of micron-level debris in automotive manufacturing and cleansing operations, the AQC^TM. Manufacturers have come to understand that particles smaller than can be seen by their current optical and gravimetric inspection techniques can impact production—particles that are easily be identified and characterized by the AQC^TM.

Also, unlike optical microscopes, which provide only a visual image, the ASPEX AQC^TM system identifies both the presence of foreign particles AND their elemental composition—data that can help a manufacturer pinpoint the likely source upstream in their production operations or from a supplier's component.

Leading auto makers have reduced manufacturing and warranty failures by 30%
Leading German and American manufacturers, including Ford, Mercedes, and Bosch, have installed ASPEX AQC^TM systems in their factories to reduce manufacturing and warranty failures in critical applications such as:

• Transmission assemblies
• Power Steering assemblies
• Fuel injection systems
• Diesel engines

Particles from an automatic transmission - left: optical, right: SEM/BSE.  This image also demonstrates the ability of the Electron Beams superior ability to differentiate features of interest from the background filter membrane.

Critical Cleanliness - Improving your cleanliness through monitoring

What is Critical Cleanliness?
As the physical sizes and tolerances of precision devices continue to shrink, quality-conscious manufacturers find it increasingly necessary to ensure the critical cleanliness of their parts and processes. An important part of the challenge is to develop and monitor adequate cleaning procedures—but how does one know whether one's protocol is performing optimally?

One common class of contamination problems arises when a manufacturer needs to verify that its product is suitably free of a specific kind or class of particulate contaminant, such as a toxic or abrasive material. The challenge in such cases is that the targeted particles are, one hopes, rare, or even absent entirely. To achieve the necessary statistical precision, quite a large sample area may need to be searched, and an inordinate amount of time could be wasted examining "benign" materials present. In such a "needle-in-a-haystack" problem, the challenge is to rapidly screen for candidate particles.

This is where ASPEX's Perception^TM AFA software plays a key role. By appropriate selection of the back-scatter contrast thresholds and the dynamic search grid, large areas of "empty" sample can be rapidly traversed without sacrificing sensitivity to the "bad actors." The analysis can automatically terminate when the necessary precision is fulfilled, and go/no-go decisions can be automatically generated.

The more general class of contamination problem involves screening for "foreign" materials of a general and largely unpredictable nature. Here the challenge is to identify and classify large quantities of particles over a wide range of sizes, shapes, and compositions, realizing that the particles of greatest interest may not be known until after the analysis. For such applications, Perception CFA offers distinct advantages with its ability to accurately characterize particles of arbitrary shape. CFA, like AFA, can also rapidly characterize large numbers of particles, employing user-defined rules to automatically classify particles, in appropriate classes, and includes provisions for employing or suppressing elemental analysis and storing thumbnail images for post-analysis. The ability to relocate specific particles for manual inspection following the analysis can be a vitally important capability in such applications when unexpected particle types are encountered. Knowledge of particle morphology and composition becomes primary evidence in the identification of the contamination source.

Regardless of whether it's Perception^TM AFA or CFA that is employed, comprehensive reports can be generated and customized spreadsheet reports automatically generated by means of the Tabular Reporter. Population of an iStore database permits long-term trend analysis.

Easily load and analyze up 10 – 25 mm diameter filters membranes, or 5 – 47 mm diameter filter membranes.

Attainability of Complete Cleanliness
Complete Cleanliness is probably not attainable—but is it necessary?  Producing large quantities of a significant number of parts that must move through a highly complex assembly process cannot reasonably be expected to result in components containing zero particle contaminants.

Complex cleaning processes have been employed throughout the production process and these efforts have resulted in a significant reduction in the presence of particulate contaminants.  So if particles can be removed from components, but not to a state of complete particle cleanliness, is there a level that can be attained that provides the required benefits?  How do we know when we have reached that level?

Design and production engineers employing the monitoring of cleanliness as part of their quality systems, have been developing an understanding as to the cleanliness levels required by each of their components – the “Critical Cleanliness” requirement of that component.

As clean as necessary has become the target design that production engineers have established for their efforts.  Achieving an understanding of the Critical Cleanliness level for a component can be a difficult and time-consuming effort. Therefore, engineers have begun to develop a process of continuous improvement that allows the cleanliness effort to improve as information is generated and studied over time.