Search Results for dimensional inspection

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.

The coordinate measuring machine (CMM) is used for three-dimensional inspection of both in-process and finished parts. This chapter provides a detailed account of the operating principles, measurement techniques, capabilities, and applications of CMMs. The types of CMMs are described. Vertical CMMs include cantilever-type, bridge-type, and gantry CMMs; horizontal CMMs, such as the horizontal-arm type, are also covered. The CMM application for geometric measurement, contour measurement, and specialized surface measurement are discussed.

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.

This appendix is a compilation of suggested analysis methods for suspected component failure causes.

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.

A product pedigree describes its design and how it was built and shows that it was built in accordance with the drawings and other documentation defining the product configuration. Evaluating the pedigree of a failed product can help to rule in or rule out hypothesized failure causes. This chapter describes various areas that can be examined by the failure analysis team to assess the pedigree of the failed system. If the failure analysis team suspects product pedigree anomalies it should confirm conformance through independent means.

This chapter focuses on common failure characteristics exhibited by mechanical and electrical components. The topic is considered from two perspectives: one possibility is that the system failed because parts were nonconforming to drawing requirements and another possibility is that the system failed even though all parts in the system met their drawing requirements. The common failures discussed in this chapter include those associated with metallic components, composite materials, plastic components, ceramic components, and electrical and electronic components.

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.

After pouring, castings are allowed to solidify and cool. They are later removed from the molds in the shakeout operation. A series of activities then follow, which are generally referred to as finishing and heat treatment. These activities can be broadly categorized as shakeout, abrasive blast cleaning, removal of risers, ingates, and discontinuities, rough inspection, removal of discontinuities, finishing welding, heat treatment, and final visual, dimensional, and NDT inspection. This chapter provides a detailed discussion on these activities.

Fabricated powder metallurgy (P/M) parts are evaluated and tested at several stages during manufacturing for part acceptance and process control. The various types of tests included are dimensional evaluation, density measurements, hardness testing, mechanical testing, and nondestructive testing. This chapter is a detailed account of these testing methods. It describes the four most common types of defects in P/M parts, namely ejection cracks, density variations, microlaminations, and poor sintering. The chapter discusses the capabilities and limitations of various nondestructive evaluation methods to flaw detection in P/M parts. The nondestructive evaluation methods covered are mechanical proof testing, metallography, liquid penetrant crack detection, filtered particle crack detection, magnetic particle crack inspection, direct current resistivity testing, x-ray radiography, computed tomography, gamma-ray density determination, and ultrasonic techniques.

This chapter discusses field, visual, physical, and metallurgical examinations of gear failures. Physical examinations reviewed include nondestructive testing, including magnetic-particle inspection, tooth characteristic studies, surface hardness testing, ultrasonic testing, nital etching, profilometer measurements, and dimensional checking. Metallurgical examinations reviewed include the cross-sectional hardness survey, macroscopic examination, carbon gradient traverse, chemical analysis, case hardness traverse [microhardness], microscopic examination, and scanning electron microscopy.

The aim of every extrusion plant is the efficient production of competitive products that meet the appropriate quality requirements. This chapter discusses the processes involved in the selection and introduction of a quality management system, along with its application, advantages, and disadvantages. It describes the process chain for order processing within the quality circle and provides information on product liability legal issues. In addition, the chapter discusses the processes involved in quality control, along with its organization, responsibilities, audits, and testing.

Machine vision is a means of simulating the image recognition and analysis capabilities of the human eye/brain system with electronic and electromechanical techniques. This chapter discusses four basic steps in the machine vision process, namely image formation, image preprocessing, image analysis, and image interpretation. Details of the processes involved, equipment used, and the factors to be considered are also presented. In addition, the applications of machine vision are discussed.

This chapter discusses the application of investment casting to nickel- and cobalt-base superalloys. It describes the production of polycrystalline and single crystal castings, the materials normally used, and the part dimensions and tolerances typically achieved. It explains how patterns, molds, and shells are produced, discusses the practice of directional solidification, and examines an assortment of turbine components cast from nickel- and cobalt-base alloys. The chapter also addresses casting problems such as inclusions, porosity, distortion, core shift, and leaching and explains how to avoid them.

This chapter is a detailed account of various factors pertinent to the development and launch of a product. It begins by describing the five phases in the product launch process, namely product design and development, process design and development, product and process validation, product launch, and continuous improvement. This is followed by sections covering product-process flow diagrams and also the process elements considered for process failure mode and effects analysis. Some of the aspects covered by the engineering specifications to meet the product performance requirements are then reviewed. Details on product validation requirements and definitions of parameters related to the launch process are also provided. The chapter discusses the purpose of manufacturing control plan, along with an illustration of a manufacturing control plan outlined for a safety-critical suspension casting. It ends with an overview of the contents of a program launch manual.

This chapter discusses the processes and guidelines for selecting a supplier and for specifying and purchasing steel castings. It details the information that is most useful to the casting supplier and purchaser.

This chapter discusses the role of standards and specifications for steel castings. It defines specifications and discusses how certification, testing, examination, methods, practices, procedures, compositions, properties, facilities, statistical process control, and documentation relate to codes and standards. The chapter describes processes involved in the selection of specifications for steel castings. Further, it provides information on the cost of specifications.