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SEM · EDX · FTIR · Cross-Sectioning · Root Cause Investigation ISO/IEC 17025 Accredited Testing Where Applicable | SEM EDX FTIR Cross-Section Support | Automotive Failure Analysis A component can fail in many ways. It may crack during qualification testing, return from the field with corrosion, show a coating defect, or fail electrically without an obvious surface mark. The first question is usually what failed. The more useful question is why it failed. Scanning electron microscopy analysis is one of the key techniques used in automotive failure investigation because it can examine fracture surfaces, corrosion features, particles, coatings and surface defects at much higher magnification than optical microscopy. It is rarely used alone. A stronger investigation usually combines SEM with EDX, FTIR, cross-sectioning and background information from the component’s service or production history. A good failure analysis does not jump straight to the highest magnification. It starts with the least destructive checks, builds evidence step by step, and only cuts or alters the sample when the investigation has a clear reason to do so. What Happens During Failure Analysis Failure analysis is a structured investigation used to understand the physical, chemical or mechanical evidence behind a component failure. The aim is not simply to take microscope images. The aim is to connect the observed damage with the most likely failure mechanism and the conditions that caused it. A typical investigation moves from broad observation to targeted analysis. Stage What it does Why it matters Visual and optical examination Documents the sample as received and locates the failure area Preserves evidence before cutting, cleaning or coating SEM imaging Examines fracture surfaces, corrosion, particles or surface defects at high magnification Shows fine surface features that optical microscopy may miss EDX analysis Detects elemental signals from selected areas or particles Supports material, contamination or corrosion hypotheses FTIR spectroscopy Identifies organic materials such as polymers, oils, coatings or residues Useful for non-metallic contamination and polymer-related failures Cross-sectioning Cuts and polishes the sample to reveal internal structure Shows coating layers, interfaces, crack paths, porosity or solder joint features The order can change depending on the sample, but the principle is the same. Non-destructive documentation should come first. Destructive preparation should come later, once the analyst knows what evidence needs to be exposed. Visual and Optical Examination The first stage is simple but important. The laboratory documents the sample condition, photographs the failure area and records visible features such as cracks, corrosion, staining, deformation, wear marks or coating damage. Stereo microscopy gives a low magnification overview with depth of field. This helps the analyst decide where to examine next with SEM or where a cross-section should be taken. Skipping this stage can remove context that may be needed later, especially if the sample is cut, cleaned or mounted. Scanning Electron Microscopy Analysis SEM uses a focused electron beam to scan the sample surface and create high magnification images. In failure analysis, this is especially useful for fracture surfaces and rough three-dimensional features. On a broken metal part, SEM may show features that support a fatigue, overload, brittle fracture or wear-related interpretation. Fatigue striations, where present, can indicate progressive crack growth. Dimpled features may support ductile overload. Cleavage-like facets may support brittle fracture. These features are not interpreted in isolation; they must be considered with material, loading history, geometry and service conditions. SEM is also useful for corrosion deposits, coating defects, particles, contamination and surface damage. It can show morphology clearly, but it does not identify every chemical compound by itself. That is why SEM is often paired with EDX. What EDX Adds to SEM EDX, also written as EDS, detects characteristic X-rays emitted from the sample when it is examined under the electron beam. This allows the analyst to identify elements present in a selected point, area or particle. For example, EDX may detect chlorine, sulfur, oxygen, iron, aluminium, copper, silicon or other elemental signals. These signals can support a corrosion, contamination or material transfer hypothesis. However, EDX should not be described as confirming a specific compound on its own. Detecting chlorine does not automatically prove a defined chloride compound, and detecting sulfur does not automatically prove sulfate. The result needs to be interpreted with the sample condition, morphology and any supporting tests. FTIR for Organic Materials and Residues SEM and EDX are strong tools for imaging and elemental analysis, but they are not the best choice for identifying organic materials. FTIR is used when the question involves polymers, coatings, adhesives, oils, elastomers or residue films. FTIR measures how a material absorbs infrared light and produces a spectrum that can be compared with reference data. In automotive failure analysis, FTIR may help identify a seal material, a polymer contaminant, an adhesive residue, a coating film or degraded organic material found near the failure area. Cross-Section Analysis Some failures cannot be understood from the surface. Cross-section analysis is used when the investigation needs to see inside the material, coating, solder joint, plated layer or bonded interface. The sample is mounted, cut, ground and polished to expose the area of interest. In metals, etching may be used to reveal microstructure. In coatings or electronics, the cross-section can show layer thickness, voids, cracks, delamination, porosity or interface defects. Because cross-sectioning permanently changes the sample, it should be performed after visual and surface examination. The cut location should be chosen based on the evidence already collected. Which Technique Fits Which Failure Different failure symptoms need different evidence. The table below gives a practical starting point, but the final test plan should be based on the sample condition and investigation objective. Failure symptom Useful techniques Evidence the laboratory may look for Cracked metal component Visual exam, SEM, EDX, cross-sectioning Crack origin, fracture mode, inclusions, corrosion or overload features Corroded connector Visual exam, SEM, EDX, FTIR where residue is present Corrosion morphology, elemental signals, residue or film identification Coating defect Optical exam, cross-sectioning, SEM, FTIR Coating thickness, adhesion issue, contamination, interface condition Polymer or rubber failure FTIR, optical exam, SEM where needed Material identification, degradation, contamination or surface damage Unknown particles or residue SEM-EDX, FTIR Elemental profile, organic material type or possible contamination source A single technique may answer part of the issue, but most root cause work needs multiple evidence streams. SEM can show how a surface failed. EDX can add elemental information. FTIR can identify organic residue. Cross-sectioning can show what happened below the surface. Example Investigation Consider an automotive connector returned from the field after intermittent electrical failure. Visual examination may show staining around the contact area. SEM can examine the contact surface at higher magnification and show corrosion morphology or particles between contacts. EDX can detect elemental signals such as chlorine, sulfur, copper, tin or other elements that support a contamination or corrosion hypothesis. If a film or residue is present, FTIR may help identify whether it is an oil, polymer, adhesive residue or process-related organic material. If moisture ingress or seal failure is suspected, a cross-section through the sealing area can show whether the interface, seal geometry or housing condition contributed to the failure. The conclusion should be based on all of the evidence, not on one image or one spectrum alone. What to Prepare Before Sending a Sample Failure analysis is more focused when the laboratory receives both the failed part and the right background information. Prepare the following where available. Component name and function Failure symptom and when it was discovered Whether the sample came from production, qualification testing or the field Material grade, coating, plating or surface treatment Operating environment such as heat, humidity, vibration or chemical exposure Number of failed samples and number of good comparison samples Photos before removal or cleaning, if available Any previous test data or inspection records What decision the report needs to support, such as root cause, corrective action or customer response Avoid cleaning, cutting or altering the failed area before submission unless the laboratory advises it. If comparison samples are available, include them. A good part from the same lot can make the investigation much stronger. What a Failure Analysis Report Can and Cannot Do A failure analysis report can identify observed damage, describe the evidence, explain the likely failure mechanism and support an evidence-based root cause conclusion. In many cases, it can also suggest contributing factors or recommend what process area should be checked next. It should not be treated as a legal judgement by itself. Whether the root cause becomes supplier responsibility, design issue, production escape, misuse or field exposure depends on technical evidence plus contractual and commercial context. Turnaround time also depends on scope. A simple SEM-EDX examination may be faster than a multi-technique investigation involving cross-section preparation, FTIR and comparison samples. If the case is urgent, the timing should be discussed before the test plan is confirmed. Frequently Asked Questions Do I need to know which technique I need before contacting a laboratory No. You can send the failure description, photos and available background information first. The laboratory can recommend whether SEM, EDX, FTIR, cross-sectioning or another method is appropriate. What is scanning electron microscopy analysis used for Scanning electron microscopy analysis is used to examine fine surface features such as fracture morphology, corrosion deposits, wear marks, particles, coating defects and contamination. It helps show details that are not visible with normal optical microscopy. Can SEM and EDX identify the exact cause of corrosion They can support a corrosion investigation by showing morphology and elemental signals. They may indicate the presence of elements such as chlorine, sulfur or oxygen. The exact cause still depends on supporting evidence such as service history, material condition, environment, residue analysis and process data. Is failure analysis only for metal components No. Failure analysis can be applied to metals, polymers, rubber, coatings, adhesives, electronics materials and composites. The technique selection depends on the material and the failure symptom. Is every failure analysis result covered by ISO/IEC 17025 accreditation Not necessarily. ISO/IEC 17025 accreditation applies to specific methods within a laboratory’s accredited scope. If accredited results are required for submission, confirm the exact method and scope before testing begins. Go Deeper into SEM Analysis This article explains SEM as part of a broader failure analysis workflow. For a more detailed technical guide to SEM imaging, magnification, sample preparation and limitations, read the dedicated SEM Analysis for Automotive Failure Investigation article. Request a Failure Analysis Quote ALS Testing can support automotive failure analysis for cracked components, corrosion, coating defects, contamination, polymer issues and field-returned assemblies. Testing under ISO/IEC 17025 accreditation is available where covered by the applicable accredited scope. Share the sample condition, failure background and required report purpose so the laboratory can recommend the right investigation plan. Next Steps Back to Failure Analysis Hub for the full service overview at  https://www.alstesting.co.th/failure-analysis-services-sem-ftir-edx-als-testing/  Read the detailed SEM Analysis guide for automotive failure investigation Explore FTIR material identification capabilities for automotive materials Contact our team to discuss a failure analysis investigation at https://www.alstesting.co.th/contact-us/  ISO/IEC 17025 Accredited Testing Where Applicable | SEM EDX FTIR Cross-Section Support | Automotive Failure Analysis

When an automotive component fails in the field, or returns from an OEM qualification test with an unexplained result, the investigation eventually reaches a question that cannot be answered with a magnifying glass. The fracture surface looks unusual under optical microscopy, but the relevant features are below the resolution limit. The corrosion morphology suggests a specific mechanism, but you cannot confirm it from a visual examination. A particle was found on a critical surface, but its identity and origin are unknown. Scanning electron microscopy resolves that question. SEM is the analytical bridge between what you can observe at the macro scale and what you need to know at the micro and nano scale. It is the single most powerful imaging tool available for failure analysis work in automotive manufacturing, and it is the technique that separates a surface-level investigation from a definitive root cause conclusion. This article explains how SEM analysis works, what makes it uniquely suited to automotive failure investigation, and the specific applications where it delivers information that no other technique can provide. How Scanning Electron Microscopy Works Optical microscopy uses visible light to form an image. The resolution limit of optical microscopy is set by the wavelength of light, which constrains maximum useful magnification to approximately 1,000 to 2,000 times. Beyond that limit, the image becomes blurred rather than more detailed. For many failure analysis scenarios, this is insufficient. Fatigue striations, grain boundary features, corrosion pit morphology, and the surface texture of fracture faces all occur at scales that demand higher resolution. Scanning electron microscopy replaces the light beam with a focused beam of electrons. Electrons have a wavelength several orders of magnitude shorter than visible light, which is what allows SEM to achieve resolution several hundred times greater than optical microscopy. The practical result is that SEM can produce sharp, detailed images at magnifications from approximately 20 times up to 100,000 times or higher, with a depth of field that is far greater than optical microscopy at equivalent magnifications. The operating principle is sequential scanning. The electron beam is rastered across the sample surface in a grid pattern. At each point, the beam interacts with the sample and generates signals that are detected and used to construct the image. The most commonly used signal in standard SEM imaging is secondary electrons, which are low-energy electrons ejected from the sample surface by the primary beam. Because secondary electron emission is highly sensitive to surface topography, secondary electron images show the three-dimensional texture of the sample surface with exceptional clarity. A second commonly used signal is backscattered electrons, which are primary beam electrons reflected back from the sample by elastic scattering. Backscattered electron intensity is strongly dependent on the atomic number of the elements in the sample: heavier elements appear brighter and lighter elements appear darker. This makes backscattered electron imaging valuable for identifying compositional contrast across a sample surface, for example distinguishing different phases in an alloy microstructure or identifying heavy-element inclusions in a polymer matrix. SEM gives you the surface of a component or fracture face at a scale where the failure mechanism leaves its clearest physical record. What happened to a component is written in features that are tens to hundreds of micrometres in size. SEM reads that record.   Sample Preparation for SEM Most metallic and ceramic samples can be imaged directly in the SEM without preparation, provided they are clean and appropriately sized for the sample chamber. Non-conducting samples, including most polymers, rubber, and unfilled ceramics, require a thin conductive coating applied by sputter deposition, typically gold, platinum, or carbon, to prevent the sample surface from charging under the electron beam. Charging causes image distortion and artefacts that interfere with analysis. The coating layer is typically 5 to 20 nanometres thick and does not obscure the surface features of interest. For cross-section analysis, samples are prepared by cutting through the area of interest, embedding in a low-shrinkage resin, and grinding and polishing to a metallographic finish. This reveals the internal structure of the component at the cut plane, including coating layers, grain structure, crack paths, and interface morphology, all of which can then be imaged and analysed by SEM. Sample preparation is a critical step that directly affects the quality of SEM results. Contamination introduced during preparation, or damage to fracture surfaces from careless handling, can mask or destroy the very features the analysis is designed to reveal. Experienced analysts handle samples with this in mind from the moment of receipt.   SEM Resolution and Magnification & What the Numbers Mean in Practice Resolution and magnification are related but distinct concepts. Magnification tells you how many times larger the image is than the object. Resolution tells you the smallest feature the instrument can distinguish as separate from its neighbour. Modern SEM instruments achieve practical working resolution of 3 to 20 nanometres depending on the instrument type and operating conditions. For most automotive failure analysis work, working resolution of 10 to 50 nanometres is sufficient to resolve the features of interest. In practice, the resolution achieved on a real sample depends on the sample condition, the accelerating voltage used, and the detector configuration. For most failure analysis work in automotive applications, working resolution of 10 to 50 nanometres is sufficient to resolve the features of interest. The magnification range that covers most automotive failure analysis work is from 50 times to 10,000 times. At 50 to 200 times, SEM provides overview imaging of fracture surfaces and corrosion zones that gives context before higher magnification is applied. At 500 to 2,000 times, the characteristic features of specific failure mechanisms become clearly visible: fatigue striations, cleavage facets, intergranular fracture paths, corrosion pit morphology. Above 5,000 times, fine microstructural features, nano-scale corrosion products, and the surface morphology of individual particles can be resolved.   Magnification Range     What It Shows Typical Application 20x to 200x Overview of fracture faces, corrosion zones, large defects Initial characterisation, failure site mapping 200x to 1,000x Fracture morphology, crack initiation sites, gross microstructural features Failure mechanism identification 1,000x to 5,000x Fatigue striations, cleavage facets, grain boundary details, corrosion pits Root cause determination, mechanism confirmation 5,000x to 20,000x Fine microstructural features, corrosion product morphology, thin film details Detailed mechanism analysis, corrosion characterisation 20,000x and above Nano-scale features, particle surface morphology, ultra-thin coating details Advanced characterisation, research-level analysis   SEM-EDX Combining Imaging with Elemental Analysis SEM imaging tells you what a feature looks like. Energy-dispersive X-ray spectroscopy (EDX), also written EDS, tells you what it is made of. The two techniques are routinely operated together, using the same electron beam in the same instrument, and together they are more powerful than either technique alone. When the primary electron beam interacts with the sample, it generates X-rays whose energies are characteristic of the elements present. Each element produces X-rays at specific, known energies: iron at 6.4 keV, aluminium at 1.49 keV, chlorine at 2.62 keV, and so on. The EDX detector measures the energy and intensity of these X-rays, producing a spectrum that identifies which elements are present and at what relative concentrations. In automotive failure analysis, SEM-EDX is applied in three primary ways. Point analysis targets a specific feature identified in the SEM image and produces an elemental spectrum for that location. This is used to identify a corrosion product, confirm the composition of an inclusion, or characterise a contaminating particle. Area analysis averages the elemental composition across a defined region of the sample, providing a bulk compositional snapshot. Elemental mapping uses the EDX signal to construct colour-coded maps showing where specific elements are distributed across the imaged area, revealing elemental gradients, segregation, and the spatial relationship between different phases or contamination layers. The combination of SEM morphological imaging and EDX elemental identification is the most information-dense single analytical step available in failure analysis. It simultaneously answers what happened and what it happened to. EDX does have limitations that experienced analysts account for. It is a surface technique with a sampling depth of approximately 1 to 2 micrometres at typical operating voltages. Quantification accuracy depends on sample geometry and is less precise for light elements (below sodium in the periodic table, including carbon, nitrogen, and oxygen) than for heavier elements. For definitive quantitative analysis of light elements or trace concentrations, EDX results are confirmed by complementary techniques such as FTIR for organic identification or ICP-MS for trace elemental quantification. For a deeper look at EDX elemental analysis and its role in failure investigation, see our dedicated EDX Analysis guide: /blog/edx-analysis/ Automotive Applications of SEM Analysis SEM analysis is applied across a wide range of failure scenarios in automotive manufacturing and service. The following are the most significant application areas in the context of ALS’s failure analysis work. Fracture and Fatigue Analysis Fracture surfaces are the primary domain of SEM in automotive failure analysis. The mechanism of a fracture leaves characteristic morphological signatures on the fractured faces, and SEM imaging at appropriate magnification reveals these signatures clearly. Fatigue fractures are identified by the presence of fatigue striations: closely spaced parallel marks that represent the crack front position at each load cycle. Striations are typically visible at magnifications of 1,000 to 5,000 times, and their spacing provides information about the crack growth rate per cycle. The initiation site of a fatigue crack is identifiable in the SEM image by the convergence of striation patterns and is typically associated with a stress concentration: a surface defect, a machining mark, a corrosion pit, or an inclusion. Brittle fracture modes leave different signatures. Cleavage fracture in crystalline metals produces flat, faceted fracture surfaces aligned with specific crystallographic planes, visible in SEM as bright, planar areas with characteristic river line patterns. Intergranular fracture, where the crack propagates along grain boundaries rather than through grains, produces a faceted surface where individual grain surfaces are visible. This mode is associated with grain boundary embrittlement from hydrogen absorption, temper embrittlement, or grain boundary corrosion. Ductile overload fracture produces a dimpled surface morphology at the microscale, where micro-voids nucleate at inclusions or particles and coalesce as the material deforms. The presence and size of dimples, and whether they are equiaxed or elongated, provides information about the stress state at fracture. Corrosion Characterisation SEM imaging characterises the morphology of corrosion damage in detail that cannot be achieved by optical microscopy. Pitting corrosion is identified by the hemispherical or crystallographic pit geometry and the presence of corrosion product deposits within and around the pits. The EDX spectrum of the corrosion products identifies the mechanism: chloride-rich corrosion products indicate chloride-induced pitting, sulfate-rich products indicate sulfuric acid attack, and the presence of zinc, chromate, or other coating elements indicates breakdown of the protective layer. Crevice corrosion, galvanic corrosion at bimetallic interfaces, and stress corrosion cracking all have distinctive SEM signatures. Stress corrosion cracking produces branched or transgranular crack morphology that SEM distinguishes clearly from mechanical fatigue. Cross-section SEM imaging of corroded surfaces shows the depth and morphology of the corroded zone, the integrity of any remaining coating, and the relationship between the corrosion front and the underlying microstructure. Contaminant and Particle Identification When foreign particles are found on automotive component surfaces, in hydraulic fluids, on electrical contacts, or on PCB surfaces, SEM-EDX provides the most direct path to identification. The morphology of a particle (rounded, angular, fibrous, platelet-shaped) narrows the candidate material types. The EDX elemental composition provides positive identification: an iron-rich angular particle is consistent with machining swarf, a silicon and oxygen-rich particle suggests a silicate mineral contaminant, a carbon-rich fibrous particle indicates organic fibre contamination. This combination of morphological and compositional information is essential for contamination source investigation. Identifying not just that contamination is present but where it likely originated from allows targeted corrective action in the manufacturing process. In cleanliness testing applications where particles are extracted from precision components and collected on filter membranes, SEM-EDX analysis of specific particles from the filter provides the particle identification data required by some OEM cleanliness specifications and by failure investigations where particle composition is central to the root cause. Coating and Surface Treatment Analysis SEM cross-section analysis is the primary tool for characterising the thickness, morphology, and integrity of coatings, platings, and surface treatments on automotive components. A properly prepared cross-section through a coated surface reveals each layer in the coating stack with nanometre-scale detail: the base material microstructure, the interface between base material and coating, each individual coating layer and its thickness uniformity, and any defects such as porosity, cracking, or delamination planes within the coating. EDX line scan analysis across the cross-section shows how the elemental composition transitions from one layer to the next, identifying the composition of each layer and detecting diffusion zones, interdiffusion effects, or contaminating species at layer interfaces. This is particularly relevant for investigation of adhesion failures, where the locus of failure (whether it occurred within a layer or at an interface) determines whether the failure is a coating process problem, a surface preparation problem, or a design problem. PCB and Automotive Electronics Failure Analysis Electronic components and PCB assemblies in automotive applications are subject to increasingly stringent reliability requirements, driven by the safety-critical nature of automotive control systems. SEM analysis is central to failure investigation in this domain. Solder joint failures are characterised by SEM to distinguish fatigue-driven cracking from brittle intermetallic fracture, from dewetting and non-wet opens caused by poor solderability. The fracture morphology and the composition of the solder and intermetallic layers identified by EDX provide the evidence to determine root cause. Corrosion and dendritic growth failures on PCB surfaces are investigated by SEM to characterise the morphology of the corrosion product and identify the ionic species responsible through EDX analysis. The distribution and density of corrosion sites across the board provides information about whether contamination was local or global, which guides the corrective action. For PCB ionic contamination analysis and chemical cleanliness investigation, see our Chemical and Electronics Testing services:  https://www.alstesting.co.th/anion-test-specialist-malaysia/ SEM vs Optical Microscopy & When to Use Each SEM and optical microscopy are complementary techniques. In a structured failure analysis investigation, both are used, with optical microscopy providing the initial characterisation and SEM providing the higher-resolution detail needed to reach a definitive conclusion.   Dimension Optical Microscopy SEM Analysis Maximum useful magnification    1,000x to 2,000x Up to 100,000x or higher Resolution 0.2 micrometres (diffraction limited) Typically 3 to 20 nm (varies by instrument/settings) Depth of field Low – challenging for rough fracture surfaces High – excellent for three-dimensional surfaces Colour imaging Yes – colour information from reflected light No – greyscale images only (BSE gives compositional contrast) Elemental analysis Not available Available via EDX – point, area, and map Sample preparation Minimal for most samples Coating required for non-conducting samples Throughput Fast – rapid overview imaging Slower – higher setup time per sample Best application Initial survey, large-area overview, surface colour assessment High-resolution characterisation, elemental identification, fine feature analysis Cost Lower per hour Higher per hour – more information per analysis   The practical workflow in failure analysis begins with stereo microscopy for large-area overview and failure site identification, moves to optical microscopy for initial characterisation at intermediate magnifications, and then applies SEM for the high-resolution imaging and EDX elemental analysis that establishes root cause. This sequence preserves the most informative analytical steps and ensures that SEM time is focused on the features that matter most. What SEM Analysis Cannot Do Understanding the limitations of SEM is as important as understanding its capabilities. SEM is an imaging and elemental analysis technique. It is not a molecular identification technique: it can tell you that a particle contains carbon, oxygen, and iron, but it cannot tell you whether the organic phase is a polyamide, a polyester, or an epoxy. For molecular identification of organic materials, FTIR spectroscopy is the appropriate complementary technique. SEM is also a surface technique. Without cross-section preparation, it analyses only the surface of the sample. Subsurface features, internal cracks, and through-thickness compositional gradients are not visible in surface SEM imaging without sectioning. For volumetric characterisation, techniques such as serial cross-section analysis or X-ray computed tomography (available at specialist facilities) are required. EDX quantification is more accurate for heavier elements than for light elements. Carbon, nitrogen, and oxygen are detectable but quantified with lower accuracy than elements from sodium and above in the periodic table. When precise quantification of light elements is required, complementary techniques including combustion analysis or carrier gas hot extraction are used. These limitations are not reasons to avoid SEM. They are reasons to use it as part of a structured, multi-technique failure analysis programme where each technique’s output builds on and is corroborated by the others. SEM Analysis at ALS Testing ALS Testing provides SEM and SEM-EDX analysis as part of our automotive failure analysis services. Our SEM capability covers the full range of applications described in this article: fracture and fatigue analysis, corrosion characterisation, contaminant and particle identification, coating cross-section analysis, and PCB and electronics failure investigation. All SEM analysis at ALS is conducted within our ISO/IEC 17025:2017 accredited quality management system, with documented equipment calibration, analyst qualification records, and sample traceability throughout. Our reports include representative SEM images with scale bars, magnification data, and operating conditions, supported by EDX spectra and maps where elemental characterisation is part of the investigation scope. Reports are formatted to support OEM submission, warranty dispute documentation, and technical engineering review. Our failure analysis team has experience across the full range of automotive materials and component types: metals, polymers, composites, coatings, adhesives, and electronics assemblies. When a failure reaches the SEM stage, we have the context and the technical depth to connect what we see in the image to what was happening in the manufacturing process or service environment. Summary Scanning electron microscopy is the central imaging tool of automotive failure analysis. It achieves magnifications and resolutions that optical microscopy cannot reach, with a depth of field that makes it uniquely suited to imaging the rough, three-dimensional surfaces of fractures and corrosion zones. When combined with EDX elemental analysis, it identifies not just the morphology of a failure feature but the material it involves. In automotive applications, SEM analysis is applied to fracture and fatigue investigation, corrosion characterisation, contaminant and particle identification, coating and surface treatment analysis, and PCB and electronics failure investigation. It is the technique that converts a visible failure into a defensible root cause conclusion, supported by documented images and data that hold up in OEM review, warranty proceedings, and regulatory submissions. Next Steps See our Failure Analysis services and full SEM capability overview:  https://www.alstesting.co.th/failure-analysis-services-sem-ftir-edx-als-testing/ Read our guide to EDX elemental analysis in failure investigation: /blog/edx-analysis/ For PCB and electronics failure analysis including ionic contamination: https://www.alstesting.co.th/anion-test-specialist-malaysia/ Contact our team to discuss a failure investigation: https://www.alstesting.co.th/contact-us/