Search Results for ultrasonic embedding

This article provides an overview of the implementation of wire embedding with ultrasonic energy and thermal embedding for polymer additive manufacturing, discussing the applications and advantages of the technique. The mechanical and electrical performance of the embedded wires is compared with that of other conductive ink processes in terms of electrical conductivity and mechanical strength.

Ultrasonic additive manufacturing (UAM) is a solid-state hybrid manufacturing technique that leverages the principles of ultrasonic welding, mechanized tape layering, and computer numerical control (CNC) machining operations to create three-dimensional metal parts. This article begins with a discussion on the process fundamentals and process parameters of UAM. It then describes metallurgical aspects in UAM. The article provides a detailed description of a wide range of mechanical characterization techniques of UAM, namely tensile testing, peel testing, and pushpin testing. The article ends with information on sensor embedding.

The majority of currently used additive manufacturing (AM) processes are solidification based (SAM). Another class of AM processes consists of those that rely on deformation (DAM) to place material instead of solidification. Although SAM processes are much more widely used, as research and development continues in DAM processes, they are becoming increasingly attractive, especially for the AM of metals. This article discusses some of the more widely used DAM processes, namely ultrasonic additive manufacturing, cold spray process, and friction stir welding, focusing on their applications, advantages, and limitations.

The ultrasonic additive manufacturing (UAM) process consists of building up solid metal objects by ultrasonically welding successive layers of metal tape into a three-dimensional shape with periodic machining operations to create detailed features of the resultant object. This article provides information on the materials, welding parameters, process consumables, procedures, and applications of the UAM. It describes the methods for determining metallurgical and mechanical properties of solid metal parts to assess the range of materials and applications for which the process is suited. These methods include peel testing, push-pin testing, and microhardness/nanohardness testing. The article also reviews the issues to be addressed in maintaining UAM fabrication quality.

Ultrasonic cleaning involves the use of high-frequency sound waves that is above the upper range of human heating, or about 18 kHz, to remove a variety of contaminants from parts immersed in aqueous media. This article describes the process, design considerations and the equipment in ultrasonic cleaning. The components used in the generation of ultrasonic wave include piezoelectric and magnetostrictive transducers that are used in ultrasonic generators and tanks. The effects of solution type and its temperature on the effectiveness of ultrasonic cleaning are also discussed.

This article discusses the attempts made by the industry to create sensing approaches for modeling a process, part, and chemistry and kinetics. It reviews microwave curing of thick-section composites and the resin cure sensors that are used for resin cure monitoring. These include dielectric cure sensors, fiberoptics-based resin cure sensors, ultrasonics-based resin cure sensors, and dosimetry-based resin cure sensors. The article provides information on the resin cure control flow sensing, flow modeling, flow mapping, and resin flow. It addresses some practical issues in sensing resin cure and flow.

Ultrasonic welding (UW), as a solid-state joining process, uses an ultrasonic energy source and pressure to induce oscillating shears between the faying surfaces to produce metallurgical bonds between a wide range of metal sheets and wires. This article reviews the models of the ultrasonic welding with an emphasis on governing equations, material behavior, and heat generation of the process. It discusses the resulting factors, namely, vibration, friction, temperature, and plastic deformation as well as the bonding strength and its mechanism.

Fracture surfaces are fragile and subject to mechanical and environmental damage that can destroy microstructural features. This article discusses the importance of care and handling of fractures and the factors that need to be considered during the preliminary visual examination. It describes the procedures for sectioning a fracture and opening secondary cracks as well as the effect of nondestructive inspection on subsequent evaluation. The article provides information on the most common techniques for cleaning fracture surfaces. These techniques are dry air blast cleaning, replica stripping, organic-solvent cleaning, water-base detergent cleaning, cathodic cleaning, and chemical-etch cleaning.

The success of a reliable non-destructive evaluation (NDE) application depends greatly on the expertise and thoroughness of the NDE engineering that is performed. This article discusses the general considerations of NDE in terms of NDE response and NDE system management and schedule. It describes the NDE engineering and NDE process control, along with some case studies related to the applications of NDE. The article reviews various models for predicting NDE reliability, such as ultrasonic inspection model, eddy current inspection model, and radiographic inspection model. It concludes with an example that illustrates the integration of an ultrasonic reliability model with a CAD system.

This article focuses on nondestructive inspection of steel bars. The primary objective in the nondestructive inspection of steel bars and wire is to detect conditions in the material that may be detrimental to the satisfactory end use of the product. The article discusses various types of flaws encountered in the inspection of steel bars, including porosity, inclusions, scabs, cracks, seams, and laps. Inspection methods, such as magnetic-particle inspection. liquid penetrant inspection, ultrasonic inspection, and electromagnetic inspection, of steel bars are also described. The article provides a discussion on electromagnetic systems, eddy-current systems, and magnetic permeability systems for detection of flaws on steel bars. It concludes with a description of nondestructive inspection of steel billets.

This article focuses on the aspects associated with inspection related to pressure vessels and pipework. These aspects include inspection policy, inspection planning and procedures, inspection strategy, inspection methodology, preparation for inspection, invasive inspection, internal visual inspection, and non-invasive inspection. Inspection execution, risk-based inspection, competence assurance of inspection personnel, inspection coverage, inspection periodicity, inspection anomaly criteria, assessment of fitness, and reporting requirements, are also discussed. The article addresses the data acquisition, reporting and trending, and review and audit for the inspection. It reviews inspection techniques, including visual inspection, ultrasonic inspection, and radiographic inspection.

Ceramics usually require some form of machining prior to use to meet dimensional and surface quality standards. This article focuses on abrasive machining, particularly grinding, and addresses common methods and critical process factors. It covers cylindrical, centerless, and disk grinding and provides information on tooling, wheel selection, work material, and operational factors. It also discusses precision slicing and slotting, lapping, honing, and polishing as well as abrasive waterjet, electrical discharge, laser, and ultrasonic machining.

This article discusses the inspection/reference standards that are absolutely critical for proper application of ultrasonic inspection systems. Many of the standards and specifications for ultrasonic inspection require the use of standard reference blocks. The article lists the variables that should be considered when selecting standard reference blocks and describes the three types of standard blocks ordinarily used for calibration or reference: area-amplitude blocks, distance-amplitude blocks, and blocks of the type sanctioned by the International Institute of Welding. It reviews the determination of area-amplitude and distance-amplitude curves of a straight-beam pulse-echo ultrasonic inspection system. The article discusses the three principal conventional manual ultrasonic sizing techniques: 6 dB drop technique, maximum-amplitude technique, and 20 dB drop technique. It provides information on the dimension-measurement applications of ultrasonic inspection methods.

Time-of-flight diffraction (TOFD) is an ultrasonic technique used to detect diffracted waves from crack tips and to size the cracks from the arrival times of those waves. This article discusses the basic considerations and provides information on probe selection, gain setting, and instrumentation of TOFD. It describes the numerous effects that result from modifying the probe characteristics. The article provides the American Society of Mechanical Engineers (ASME), the European Committee for Standardization (CEN), and the International Standardization Organization (ISO) recommendations for the reference blocks according to applicable codes and standards. It also provides the ASME, CEN, and ISO recommendations for examination of welds. The article concludes with information on the interpretation and analysis of TOFD images with an aid of sizing algorithms.

Ultrasound is an ideal modality for nondestructive evaluation (NDE) because it enables the interior of objects to be assessed without the safety and access issues associated with radiography. This article summarizes the history of array usage in NDE and its relationship to medical applications. It discusses the mathematics behind classical beamforming, full matrix capture, and total focusing methods of imaging. The article shows how ultrasonic array data can be simulated by direct numerical methods (most commonly using finite-element methods), analytical methods, or hybrid methods. It also considers various methods of comparing the performance of arrays and imaging algorithms. The article provides a comparison of various advanced and nonlinear imaging algorithm and looks at some practical industrial applications of arrays. It concludes with some future perspectives for arrays in NDE.