What is ultrasonic weld testing?
Ultrasonic Testing (UT) – This method of testing makes use of mechanical vibrations similar to sound waves but of higher frequency. A beam of ultrasonic energy is directed into the object to be tested.
How do you test a spot weld?
One conventional method for inspecting spot-welds is to observe the welded metal cross-sectionally. Another is to drive a cold chisel in between spot-welded sheets to confirm whether the sheets will pry apart.
Why spot welding is used in automobile?
Spot welding is an economical method for joining metals that is commonly used in car manufacturing plants. The method is adaptable to high speed automation and is under strict cycle times. The plants are usually fully automated and equiped with robotic cells in which different parts of the chassis are built.
What is the most commonly used method of weld inspection?
Radiographic and ultrasonic weld inspection are the two most common methods of NDT used to detect discontinuities within the internal structure of welds. The obvious advantage of both methods is their ability to help establish the weld’s internal integrity without destroying the welded component.
What is ultrasonic testing used for?
Ultrasonic testing (UT) is a non-destructive test method that utilizes sound waves to detect cracks and defects in parts and materials. It can also be used to determine a material’s thickness, such as measuring the wall thickness of a pipe.
Why ultrasonic testing is important?
The advantages of ultrasonic testing include: High penetration power, allowing for flaw detection deep within a part. High sensitivity, allowing for the detection of very small flaws. Can be used to test when only one side of an object is accessible.
What is carbon test in spot welding?
The program includes tensile test experiments to determine the spot weldability of carbon steel under two different modes of stresses. The test procedure includes the following. (1)A set of peel and lap specimens were welded under different welding condition (weld time and current). The electrode tip was 4 mm.
What is the principle of spot welding?
It works by contacting copper alloy electrodes to the sheet surfaces, whereby pressure and electric current are applied and heat is generated by the passage of current through resistive materials such as low carbon steels.
How does spot welding work?
Spot welding works by applying pressure and heat to the weld area using copper alloy electrodes. These electrodes transport an electrical current through the weld segments. As the material melts the parts are fused. At this point, the current is turned off and pressure from the electrodes is upheld.
What is the maximum frequency used in ultrasonic inspection?
around 50 MHz
What is the maximum frequency used in the ultrasonic inspection? Explanation: The maximum frequency that may be needed for an ultrasonic inspection is around 50 MHz. Such frequencies make it easy for the devices to detect the flaws.
What are types of ultrasonic testing?
There are several different types of ultrasonic testing, including:
- Automated Ultrasonic Backscatter Technique.
- Phased Array Ultrasonic Testing.
- Long Range Ultrasonic Testing.
- Internal Rotating Inspection Systems.
- Time of Flight Diffraction.
- Dry-Coupled Ultrasonic Testing.
- Rapid Ultrasonic Gridding (RUG)
What is non destructive ultrasonic testing of spot welds?
The non destructive ultrasonic testing of spot welds has been applied in the automotive industry for many years. Although the welds in these factories are made by controlled robots, their inspection is still being done manually and for a limited number of welds.
How to check the quality of spot welds in an automation plant?
Automation plants use two manual methods to check for the quality of the spot welds: the hammer and chisel and manual ultrasound pulse echo inspection. The hammer and chisel method is the eldest one and is a destructive method, where the spot weld is broken, and cannot be performed in a 100 % sampling. It is very laborious and produces test scrap.
What is spot welding used for?
Spot welding is an economical method for joining metals that is commonly used in car manufacturing plants. The method is adaptable to high speed automation and is under strict cycle times. The plants are usually fully automated and equiped with robotic cells in which different parts of the chassis are built.
How many spot welds are in a car body?
Typically, a car body contains about 5000 spot welds joining sheets of different thicknesses. The demand for Quality control is ever increasing due to safety requirements and demand for quality.