Search Results for inspection techniques

This chapter concentrates almost exclusively on inspection techniques related to pressure vessels and pipework. The discussion covers the general aspects associated with inspection and the key factors relevant to it. In addition, the chapter addresses processes involved in data collection and management, namely data acquisition, reporting, trending, reviewing, and auditing. Capabilities and limitations of in-service inspection techniques are discussed in the Appendix to this chapter.

Achieving the best-performing composite part requires that the processing method and cure cycle create high-quality, low-void-content structures. If voids are present, the performance of the composite will be significantly reduced. There are multiple causes of voids in composite materials; they are generally categorized as voids that are due to volatiles (such as solvents, water) or voids that result from entrapped air. This chapter describes the analysis of various types of voids. It reviews techniques for analysis of voids at ply-drops, voids due to high fiber packing, and voids that occur in honeycomb core composites. The final section of the chapter discusses void documentation through the use of nondestructive inspection techniques and density/specific gravity measurement methods.

Lightning damage in polymer composites, as in metal structures, is manifested by damage at both the macroscopic or visual level and within the material microstructure. In addition to visual damage assessment, non-destructive inspection techniques are employed to detect damage within the composite part. This chapter describes the macroeffects of a lightning strike on composites and discusses the methods involved in the assessment of microstructural damage in composites.

After the fault-tree, a failure-cause identification method has identified potential failure causes and the failure analysis team has prepared a failure mode assessment and assignment (FMA&A). The team knows specifically what to search for when examining components and subassemblies from the failed system. There are numerous techniques and technologies available for examining and analyzing components and subassemblies, which are categorized as follows: optical approaches, dimensional inspection and related approaches, nondestructive test approaches, mechanical and environmental approaches, and chemical and composition analysis for assessing material characteristics. This chapter is a detailed account of the working principle and the steps involved in these techniques and technologies.

Fracture control can be defined as a concerted effort to maintain operating safety without catastrophic failure by fracture. It requires an understanding of how cracks affect structural integrity and strength and the time that a crack can grow before it exceeds permissible size. The chapter describes some of methods used to determine maximum permissible crack size and predict growth rates. It explains how the information can then be used to control fractures through periodic inspection, fail-safe features, mandated retirement, and proof testing. It presents a number of fracture control plans optimized for different circumstances, examines the damage tolerance requirements used by different industries, and discusses various approaches for fatigue design.

In forgings of both ferrous and nonferrous metals, the flaws that most often occur are caused by conditions that exist in the ingot, by subsequent hot working of the ingot or the billet, and by hot or cold working during forging. The inspection methods most commonly used to detect these flaws include visual, magnetic particle, liquid penetrant, ultrasonic, eddy current, and radiographic inspection. This chapter provides a detailed discussion on the characteristics, process steps, applications, advantages, and limitations of these methods. It also describes the flaws caused by the forging operation and the principal factors that influence the selection of a nondestructive inspection method for forgings.

Wrought tubular products are nondestructively inspected chiefly by eddy current techniques (including the magnetic flux leakage technique) and by ultrasonic techniques. The methods discussed in this chapter include eddy current inspection, flux leakage inspection, ultrasonic inspection, magnetic particle inspection, liquid penetrant inspection, and radiographic inspection of resistance welded tubular products, seamless steel tubular products, and nonferrous tubular products. This chapter discusses the fundamental factors that should be considered in selecting a nondestructive inspection method and in selecting from among the commercially available inspection equipment. The factors covered are product characteristics, nature of the flaws, extraneous variables, rate of inspection, end effect, mill versus laboratory inspection, specification requirements, equipment costs, and operating costs.

Weldments made by the various welding processes may contain discontinuities that are characteristic of that process. This chapter discusses the different welding processes as well as the discontinuities typical of each process. It provides a detailed discussion on the methods of nondestructive inspection of weldments including visual inspection, liquid penetrant inspection, magnetic particle inspection, radiographic inspection, ultrasonic inspection, leak testing, and eddy current and electric current perturbation inspection. The chapter also describes the properties of brazing filler metals and the types of flaws exhibited by brazed joints.

This chapter provides an overview of the various inspection methods used with metals and alloys, namely visual inspection, coordinate measuring machines, machine vision, hardness testing, tensile testing, chemical analysis, metallography, and nondestructive testing. The nondestructive testing methods discussed are liquid penetrant inspection, magnetic particle inspection, eddy current inspection, radiographic inspection, and ultrasonic testing.

Most of the counterfeit parts detected in the electronics industry are either novel or surplus parts or salvaged scrap parts. This article begins by discussing the type of parts used to create counterfeits. It discusses the three most commonly used methods used by counterfeiters to create counterfeits. These include relabeling, refurbishing, and repackaging. The article presents a systematic inspection methodology that can be applied for detecting signs of possible part modifications. The methodology consists of external visual inspection, marking permanency tests, and X-ray inspection followed by material evaluation and characterization. These processes are typically followed by evaluation of the packages to identify defects, degradations, and failure mechanisms that are caused by the processes (e.g., cleaning, solder dipping of leads, reballing) used in creating counterfeit parts.

The inspection of castings normally involves checking for shape and dimensions, coupled with aided and unaided visual inspection for external discontinuities and surface quality. This chapter discusses methods for determining surface quality, internal discontinuities, and dimensional inspection. Casting defects including porosity, oxide films, inclusions, hot tears, metal penetration, and surface defects are reviewed. Liquid penetrant inspection, magnetic particle inspection, eddy current inspection, radiographic inspection, ultrasonic inspection, and leak testing for castings are discussed. The chapter provides information on the procedures involved in the inspection of castings that are limited to visual and dimensional inspections, weight testing, and hardness testing. It also discusses the use of computer equipment in foundry inspection operations.

This chapter discusses the critical soldering faults that lead to quality degradation and potential failure of a soldered connection. It then describes the types of nondestructive evaluations used to inspect soldered and brazed joints, including dimensional and visual inspection, ultrasonic testing, radiographic examination, dye penetrant inspection, and leak testing, including overpressure tests. The chapter also provides an overview of destructive physical analysis.

Leaks can occur as the result of several failure causes. This chapter reviews the causes, features, and impact of various types of leaks, namely gasket leaks, O-ring leaks, bond-joint leaks, weld leaks, polyvinyl chloride leaks, valve leaks, and structural leaks.

A successful heat treating operation is determined by the ability to satisfy the customer's quality requirements consistently and economically. This chapter reviews the steps that are important to produce quality parts in heat treating with a brief practical explanation of each. The steps include selecting proper material and design of the part being treated; determining whether the process is capable of heat treatment; using statistical process control, control charting, and in-process inspection and testing; and applying statistical quality control and final testing (sampling) to verify the results.

This chapter discusses the methods and procedures used for inspecting induction-hardened parts. It provides information on hardness and case depth measurements, nondestructive testing and surface analysis, the effect of various hardening errors, and relevant test standards.

This chapter presents a step-by-step approach for analyzing the causes of nonconforming workpieces and determining potential solutions. The discussion covers a wide range of issues, including testing errors, latent and process-related defects, examination and testing techniques, defect characterization, and effective remedial actions.

This article reviews nondestructive and destructive test methods used to characterize welds. The first process of characterization discussed involves information that may be obtained by direct visual inspection and measurement of the weld. An overview of nondestructive evaluation is included that encompasses techniques used to characterize the locations and structure of internal and surface defects, including radiography, ultrasonic testing, and liquid penetrant inspection. The next group of characterization procedures discussed is destructive tests, requiring the removal of specimens from the weld. The third component of weld characterization is the measurement of mechanical and corrosion properties. Following the discussion on the characterization procedures, the second part of this article provides examples of how two particular welds were characterized according to these procedures.

This chapter presents various case histories that illustrate a variety of failure mechanisms experienced by the high-strength steel components in aerospace applications. The components covered are catapult holdback bar, AISI 420 stainless steel roll pin, main landing gear (MLG) lever, inboard flap hinge bolt, nose landing gear piston axle, multiple-leg aircraft-handling sling, aircraft hoist sling, internal spur gear, and MLG axle. In addition, the chapter provides information on full-scale fatigue testing, nondestructive testing, and failure analysis of fin attach bolts.

As semiconductor feature sizes have shrunk, the technology needed to encapsulate modern integrated circuits has expanded. Due to the various industry changes, package failure analyses are becoming much more challenging; a systematic approach is therefore critical. This article proposes a package failure analysis flow for analyzing open and short failures. The flow begins with a review of data on how the device failed and how it was processed. Next, non-destructive techniques are performed to document the condition of the as-received units. The techniques discussed are external optical inspection, X-ray inspection, scanning acoustic microscopy, infrared (IR) microscopy, and electrical verification. The article discusses various fault isolation techniques to tackle the wide array of failure signatures, namely IR lock-in thermography, magnetic current imaging, time domain reflectometry, and electro-optical terahertz pulse reflectometry. The final step is the step-by-step inspection and deprocessing stage that begins once the defect has been imaged.

This chapter discusses the basic steps of a failure investigation. It explains that the first step is to gather and document information about the failed component and its operating history. It advises investigators to visit the failure site as soon as possible to record damages and collect test specimens for subsequent examination and chemical analysis. It also discusses the role of mechanical property testing, the use of nondestructive evaluation, and the final step of generating a report.