Vickers Hardness Test

Summary

The Vickers hardness test measures the hardness of a turbocharger's compressor wheel by pressing a pyramid-shaped diamond indentor onto the test piece with a specified force. The process involves preparing the testing machine, positioning the test piece, and adjusting the microscope lens for focus. The diamond indentor then applies pressure, and the indentation is measured using diagonal lines. The Vickers hardness value is calculated based on the test force and the indentation area, providing a precise measurement of the material's hardness.

Takeaways

• 😀 The Vickers hardness test measures the hardness of materials like a compressor wheel for a Turbocharger.
• 😀 The Vickers method uses a pyramid-shaped diamond indentor to apply a defined force on the test piece.
• 😀 After the force is applied, the indentation surface area is evaluated to determine the hardness value.
• 😀 The tester prepares the machine by inserting the Vickers indentor into the mounting device.
• 😀 The compressor wheel is placed on the support table and adjusted until the surface is in focus through a microscope.
• 😀 The right spot for the hardness test is located by moving the test piece around on the support table.
• 😀 Once everything is set, the test begins by pressing the start button and applying the test force slowly.
• 😀 The test force is held constant for a specific period, after which the indentor lifts, and the microscope returns to its original position.
• 😀 The indentation is magnified on the display screen for easy measurement of the diagonals using control knobs.
• 😀 Four measuring lines are placed at the corners of the indentation to calculate the two diagonals' lengths.
• 😀 The Vickers hardness value is calculated automatically, based on the test force divided by the area of the indentation, resulting in a hardness value of 125 for the compressor wheel.

Q & A

What is the main principle behind the Vickers hardness test?

The main principle behind the Vickers hardness test is to press a pyramid-shaped diamond indentor with an exactly defined force onto the test piece and evaluate the surface area of the indentation.

What is the first step the tester takes when preparing for the Vickers hardness test?

The tester's first step is to prepare the testing machine by inserting the Vickers indentor with the four-sided pyramid into the mounting device.

How does the tester ensure that the test piece is in focus during the Vickers hardness test?

The tester ensures the test piece is in focus by adjusting the height of the support table until the test piece surface is displayed clearly on the screen.

What does the tester do after adjusting the test piece on the support table?

After adjusting the test piece, the tester moves it around on the support table to find the right spot for the hardness test.

What happens after the tester pushes the start button for the Vickers hardness test?

Once the start button is pushed, the diamond pyramid indentor carefully touches the test piece surface, and the test force slowly increases to its specified value.

How long does the test force hold during the Vickers hardness test?

The test force holds constant for a certain period of time before the indentor lifts off the test piece.

What is displayed on the screen after the indentor lifts in the Vickers hardness test?

After the indentor lifts, the magnified indentation appears on the display screen.

How does the tester measure the indentation in the Vickers hardness test?

The tester places four measuring lines at the corners of the indentation using a control knob, and measures the length of the two diagonals.

How is the Vickers hardness value calculated?

The Vickers hardness value is calculated by dividing the test force (F) in kiloponds by the area of the indentation (A) in square millimeters.

What is the final Vickers hardness value displayed in the script for the compressor wheel?

The final Vickers hardness value for the compressor wheel is displayed as 125.