Ultrasonic weld test

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Welding Fundamental Ultrasonic Welding Ultrasonic Testing index:: Introduction Welding Fundamental Welding Definition Weld Type Weld Shapes Weld Applications Weld Defects Welding Inspection Ultrasonic Welding Ultrasonic Testing

Text of Ultrasonic weld test

  • Eng.Haitham Shehata Hussein
  • Before we talk about we should present some info about: (Definition, Types, Shapes, Applications, Test and inspection,...)
  • In its broadest context, welding is a process in which materials of the same fundamental type or class are brought together and caused to join (and become one) through the formation of primary (and, occasionally, secondary) chemical bonds under the combined action of heat and pressure (Messler, 1993).
  • Electron Beam. Brazing . Soldering . Electric Resistance . Friction Stir . Fusion Bonding . Ultrasonic . Manual Metal . Tungsten Inert Gas . Submerged Arc . Gas Metal Arc . Metal Inert Gas Resistance Spot . Flux-Cored Arc . Laser Beam .
  • Iron and steel, stainless steel, aluminum, nickel, copper alloys Materials Steel structures, industrial fabricationApplications Fabrication shop, factory Field operations Suitable for indoor or outdoor use Typical Location Low equipment costs and wide applicability Dominant process in repair and maintenance Basically no thickness limitations Can be used in almost any position Advantages Applications are limited by welder skill Potential safety issues if not monitored Applications may require preheat Limitations Porosity, lack of fusion, incomplete penetration, and cracks Typical Discontinuities Types VT, PT, MT, RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Stainless steel, non-ferrous materials, aluminum, magnesium Materials Aerospace and space vehicles, nuclear applications, thin wall materials manufacturing applications Applications Fabrication shop, factoryTypical Location Stronger, higher quality welds Used with thin materials Greater operator control over the weld Highly resistant to corrosion and cracking Advantages Cannot be used on lead or zinc Economically not feasible for steel Slower production and difficult to master Limitations Porosity, lack of fusion, tungsten inclusions.Typical Discontinuities Types VT, PT, MT, RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Carbon steel, stainless steel, nickel-based alloys, low alloy steel, surfacing applications (i.e. weld buildup) Materials Structural and vessel construction, pipesApplications Fabrication shop, factory Suitable for indoor or outdoor use Typical Location High deposition rates deep weld penetration Little edge preparation is needed Single pass welds can be made with thick plates Arc is always covered under a blanket of flux Produces sound, uniform, and ductile welds Advantages Limited to ferrous and some nickel based alloys Limited positions and requires flux handling Limited to long straight seams or rotated pipes Requires inter-pass and post weld slag removal Limitations Porosity, inclusions, incomplete penetration, and lack of fusion. Typical Discontinuities Types VT, PT, MT, RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Sheet metal, aluminum alloysMaterials Automotive, weld studs and nuts to metal, weld screw machine parts to metal, join cross wires and bars Applications Fabrication shop, factoryTypical Location Limits the areas of excessive heating Energy controlled - more reliable welds Allows closer spacing of welds A production process can be completely automated Advantages Tends to harden the material Reduce fatigue strength Stretch or anneal the material Cause the material to warp Limitations Cracks, porosity and expulsionTypical Discontinuities Types VT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Structural steel - aluminum sections stainless steel and nickel alloys - some offshore applications Materials automotive, structural, ornamentalApplications Fabrication shop, factory - field applicationsTypical Location Versatility and speed Adaptive to robotic automation Advantages Limited to indoor use Unusable underwater Weld quality can fluctuate Limitations Dross and porosity, lack of fusion, excessive penetration, silica inclusions, cracking, undercut Typical Discontinuities Types RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Mild- and low-alloy steels, stainless steels, some high nickel alloys Materials Automotive, structural steelsApplications Factory - field applicationsTypical Location No shielding gas is required making it suitable for outdoor welding and/or windy conditions High-deposition rate process Less precleaning of metal required The weld metal is protected initially from external factors until the flux is removed Advantages When the electrode contacts the base metal, the contact tip can melt fusing it to the base metal Irregular wire feed usually the result of a mechanical problem More costly filler material/wire than GMAW Limitations Porosity, lack of fusion, inclusions, incomplete penetration, hollow bead and cracks. Also, overlap, weld spatter, underfill, and undercut. Typical Discontinuities Types VT, PT, MT, RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Carbon steel, stainless steel, aluminum, titanium Materials Automotive, aerospaceApplications FactoryTypical Location Versatile process - high quality yield Used in high volume applications Easily automated with robotics Advantages Cracking with hi-carbon steels Speed depends on type and thickness of materials Limitations Porosity, cracks, lack of fusion Also, humping and undercut Typical Discontinuities Types VT, PT, MT, RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Stainless steel, super alloys, refractory metalsMaterials Automotive, aerospace, semiconductorApplications Manufacturing facilityTypical Location Has a very small heat affected zone Is used for dissimilar metal welds Advantages Lack of penetration, lack of fusion, crackingLimitations Incomplete penetration, lack of fusion, cracks and porosity Typical Discontinuities Types VT, PT, MT, RT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Copper, brass, bronze, aluminum and othersMaterials Electrical, electronics, transportation, appliances, and construction Applications Manufacturing / field - indoors or outdoorsTypical Location Easy to learn, virtually any dissimilar metal can be joined, the bond line can be very neat in appearance, and the joint strength is strong enough for most non-heavy-duty use applications. Advantages A badly brazed joint can look similar to a good joint, and can have a very low strength. The metal used to bond the two parts may be different in color than the parts being bonded. Long-term effects of dissimilar metals in constant contact may need to be examined for special applications. Since the filler material (typically bronze) melts at a relatively low temperature, brazed parts should not be put in an environment which exceeds the melting point of the filler metal Limitations Lack of fill (unbond), porosity, cracks, and cold bond Typical Discontinuities Types VT, PT, UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Copper, silver, gold, iron, nickelMaterials Electronic components, pipe soldering, aluminum, stained glass Applications Manufacturing / field - indoors or outdoorsTypical Location Soldering can be manual or automated Formulated for maximum electrical conductivity Advantages Soldering difficulty can increase when other materials are involved Limitations Cold solder joint, oxidation, cracks and voidsTypical Discontinuities Types VTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • SteelMaterials Round / square tubingApplications ManufacturingTypical Location High production - easy automation Energy efficient Typically stronger than the material itself Very durable weld Advantages Power source and material thickness must matchLimitations Pin holes, cracksTypical Discontinuities Types VT,PT, RTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Aluminum - copperMaterials Ship building and offshore - aerospace and automotive - railway rolling stock - specialized fabrication Applications Fabrication shop, factoryTypical Location Can be used on large pieces not post weld heat treated Used where metal characteristics must remain unchanged Low concentration of discontinuities Can operate in all positions Minimum safety issues / low environment impact Advantages Exit hole left when tool is withdrawn Heavy duty clamping necessary Less flexible and often slower Limitations Cracks and lack of penetration, kissing bondsTypical Discontinuities Types UT, PTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Composites, stainless steels, alloys, ceramicsMaterials AerospaceApplications ManufacturingTypical Location Creates a bond by atomic attraction Used with MEMS fabrication / silicon Advantages Must be highly polished, clean surfaces Low strength improved by thermal treatment Limitations Laminations, lack of bondingTypical Discontinuities Types UTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT
  • Composites, plastics, dissimilar materialsMaterials Aerospace, automotive, medical, computer, packaging Applications ManufacturingTypical Location No other materials required in the process Alternative to glue, screws or snap fit Easily automated Clean, precise joints Used for electrical wire harness connections Advantages Only used for small welds Major limitation is material thickness Limited by the amount of power available Limitations Determine the presence of unbondsTypical Discontinuities Types VTNon-destructive Testing Methods Visual Testing...............................VT * Penetrant Testing.......................PT* Magnetic Particle Testing.......MT* Radiographic Testing................RT** Ultrasonic Testing.......................UT** Eddy Current Testing.................ET*** * For surface discontinuities ** For subsurface discontinuities *** For surface-breaking discontinuities and usually used to supplement PT, MT The main topic that will be discussing it later
  • Weld shapes or ( weld joints ) meaning the position of two parts that can be found when we weld it together . There is five main types for joints that allow us to get the all requirement engineering shapes. 1- Butt. 2- Lap. 3- Corner. 4- Edge. 3- T-joint.
  • Application Solutions: Oil & Gas. Power Generation. Aerospace. Automotive. Rail. Ship Building
  • Oil & Gas Power Generation
  • Aerospace Automotive
  • Rail Ship Building
  • is any flaw that compromises the usefulness of a weldment. According to the American Society of Mechanical Engineers (ASME), welding defect causes are broken down as follows: 45 percent poor process conditions, 32 percent operator error, 12 percent wrong technique, 10 percent incorrect consumables, and 5 percent bad weld grooves.
  • Hydrogen embrittlement is the process by which various metals, most importantly high-strength steel, become brittle and fracture following exposure to hydrogen. Residual stresses Are stresses that remain after the original cause of the stresses (external forces, heat gradient) has been removed. Heat from welding may cause localized expansion, which is taken up during welding by either the molten metal or the placement of parts being welded. When the finished weldment cools, some areas cool and contract more than others, leaving residual stresses.
  • The following figures give a rough survey about the classification of welding defects to DIN 8524. This standard does not classify existing welding defects according to their origin but only to their appearance.
  • Inspecting welds can reduce costs by detecting discontinuities in the early stages of manufacturing, reducing the cost of rework and extending the life of components by detecting and correcting flaws. NDT methods can identify cracking, porosity, incomplete penetration, misalignment, inclusions, lack of fusion and similar conditions, which can compromise weld strength.
  • Asset Life-Cycle Weld Inspection with Multi-Inspection Solutions:
  • Ultrasonic plastic welding is the joining or reforming of thermoplastics through the use of heat generated from high-frequency mechanical motion. It is accomplished by converting high-frequency electrical energy into high-frequency mechanical motion. That mechanical motion, along with applied force, creates frictional heat at the plastic components' mating surfaces (joint area) so the plastic material will melt and form a molecular bond between the parts.
  • In 1960 Sonobond Ultrasonics, originally known as Aerospace projects, Incorporated, developed the first metal ultrasonic welding machine to be awarded a United States Patent. Practical application of ultrasonic welding for rigid plastics was completed in the 1960s. At this point only hard plastics could be welded. The first application of this new technology was in the toy industry.
  • The first car made entirely out of plastic was assembled using ultrasonic welding in 1969. The automotive industry has used it regularly since the 1980s. Ultrasonic welding can be used now for both hard and soft plastics, such as semicrystalline plastics, and metals. Ultrasonic welding machines also have much more power now. The understanding of ultrasonic welding has increased with research and testing.
  • Ultrasonic welding equipment consists of : 1. a machine press. 2. Generator. 3. converter or transducer. 4. Booster. 5. sonotrode or horn. 6. component support tooling. A schematic of an ultrasonic welding machine is shown in Fig.1. Fig.1. Schematic of ultrasonic welding machine
  • 1-Generator The generator converts electrical power from the single-phase mains to the correct frequency and voltage for the transducer to convert into mechanical vibrations. The microprocessor unit controls the welding cycle and feeds back key welding information to the user, via the user interface. The user interface also allows the operator to enter the required welding parameters.
  • 2-Machine press The machine stand is designed to hold the welding system or stack and apply the force necessary for welding. It consists of a base-plate, to hold the tooling jig, and a pneumatic cylinder to apply the force.
  • 3-Welding stack This is the part of the machine that provides the ultrasonic mechanical vibrations. It is generally a three-part unit consisting of transducer, booster and welding horn, mounted on the welding press at the centre-point of the booster section. The stack is a tuned resonator, rather like a musical instrument tuning fork. In order to function, the resonant frequency of the tuned welding stack must closely match the frequency of the electrical signal from the generator (to within 30Hz).
  • 4-Transducer The transducer, also known as the converter, converts the electrical energy from the generator to the mechanical vibrations used for the welding process. Between each of the discs there is a thin metal plate, which forms the electrode. As the sinusoidal electrical signal is fed to the transducer via the electrodes, the discs expand and contract, producing an axial, peak-to-peak movement of 15 to 20m.Transducers are delicate devices and should be handled with care. Once the elements are broken, the transducer will not function.
  • 5-Booster The booster section of the welding stack serves two purposes, primarily to amplify the mechanical vibrations produced at the tip of the transducer and transfer them to the welding horn. Its secondary purpose is to provide a location for mounting the stack on the welding press. The booster expands and contracts as the transducer applies the ultrasonic energy. Fig.2. Ultrasonic welding boosters
  • 6-Welding horn The welding horn is the element of the welding stack that supplies energy to the component being welded. A typical welding horn is shown in Fig.3. Design of the welding horn is critical to successful welding. It is strongly recommended that welding horn manufacture should only be carried out by companies specializing in ultrasonic welding. Fig.3. Ultrasonic welding Horn
  • 7-Support tooling Finally, the base of the machine press supports the tooling that supports the components during the welding operation. The support tooling is designed to prevent movement of the lower component while the ultrasound is applied. It is often machined to match the contours of the component surface intimately.
  • The two thermoplastic parts to be assembled are placed together, one on top of the other, in a supportive nest called a fixture. Step 1 - Parts in fixture A titanium or aluminum component called a horn is brought into contact with the upper plastic part. Step 2 - Horn contact
  • A controlled pressure is applied to the parts, clamping them together against the fixture. Step 3 - Pressure applied The horn is vibrated vertically 20,000 (20 kHz) or 40,000 (40 kHz) times per second, at distances measured in thousandths of an inch (microns), for a predetermined amount of time called weld time. Through careful part design, this vibratory mechanical energy is directed to limited points of contact between the two parts . >> Step 4 - Weld time
  • The mechanical vibrations are transmitted through the thermoplastic materials to the joint interface to create frictional heat. When the temperature at the joint interface reaches the melting point, plastic melts and flows, and the vibration is stopped. This allows the melted plastic to begin cooling. The clamping force is maintained for a predetermined amount of time to allow the parts to fuse as the melted plastic cools and solidifies. This is known as hold time. (Note: Improved joint strength and hermeticity may be achieved by applying a higher force during the hold time. This is accomplished using dual pressure.) Step 5- Hold time
  • Once the melted plastic has solidified, the clamping force is removed and the horn is retracted. The two plastic parts are now joined as if molded together and are removed from the fixture as one part. Step 6- Horn retracts
  • Much faster than conventional adhesives or solvents. The drying time is very quick. The pieces do not need to remain in a jig for long periods of time waiting for the joint to dry or cure. The welding can easily be automated, making clean and precise joints. The site of the weld is very clean and rarely requires any touch-up work. The low thermal impact on the materials involved enables a greater number of materials to be welded together.
  • The applications of ultrasonic welding are extensive and are found in many industries including 1- electrical and computer, 2- automotive and aerospace, 3- medical, and packaging. Whether two items can be ultrasonically welded is determined by their thickness.
  • Ultrasonic welding machines, like most industrial equipment, pose the risk of some hazards. These include : 1. exposure to high heat levels and voltages. 2. This equipment should always be operated using the safety guidelines provided by the manufacturer in order to avoid injury. 3. For instance, operators must never place hands or arms near the welding tip when the machine is activated. 4. operators should be provided with hearing protection and safety glasses. 5. Operators should be informed of the OSHA regulations for the ultrasonic welding equipment and these regulations should be enforced.
  • In ultrasonic testing (UT), very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz and occasionally up to 50 MHz are launched into materials to detect internal flaws or to characterize materials. A common example is ultrasonic thickness measurement, which tests the thickness of the test object, for example, to monitor pipework corrosion. Ultrasonic testing is often performed on steel and other metals and alloys, though it can also be used on concrete, wood and composites, albeit with less resolution. It is a form of non-destructive testing used in many industries including aerospace, automotive and other transportation sectors.
  • In ultrasonic testing, an ultrasound transducer connected to a diagnostic machine is passed over the object being inspected. The transducer is typically separated from the test object by a couplant (such as oil) or by water, as in immersion testing. However, when ultrasonic testing is conducted with an Electromagnetic Acoustic Transducer (EMAT) the use of couplant is not required.
  • A probe sends a sound wave into a test material. There are two indications, one from the initial pulse of the probe, and the second due to the back wall echo. RIGHT: A defect creates a third indication and simultaneously reduces the amplitude of the back wall indication. The depth of the defect is determined by the ratio D/Ep
  • At a construction site, a technician tests a pipeline weld for defects using an ultrasonic phased array instrument. The scanner, which consists of a frame with magnetic wheels, holds the probe in contact with the pipe by a spring. The wet area is the ultrasonic couplant that allows the sound to pass into the pipe wall.