Brinell Hardness Test, Exams of Advanced Education

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ENGR 244 Lab 1 - BRINELL

HARDNESS TEST Mechanics of

Materials (Concordia University)

BRINELL HARDNESS TEST

BRINELL HARDNESS TEST

• Lab Report
• LAB REPORT Table of Contents
• BRINELL HARDNESS TEST
• NOMENCLATURE
• LIST OF FIGURES
• OBJECTIVE
• INTRODUCTION
• EQUIPMENT & PROCEDURE
• RESULTS- CALCULATION FOR STEEL
• RESULTS FOR STEEL
• RESULTS – CALCULATION FOR ALUMINUM
• RESULTS FOR ALUMINUM
• DISCUSSION
• CONCLUSION
• BIBLIOGRAPHY
• APPENDICES

INTRODUCTION

In the engineering world, materials have many properties including ductility, strength, resilience, resistance and many more. Among these properties, hardness of a material plays an important role in determining if a material is suitable to serve its purpose. Hardness is one of the properties of a material which helps resist deformation, breaking and indentation. Therefore, a hardness test is conducted through experiments, observations and basic theory. In order to successfully conduct a hardness test, there are four different type of tests. There is the Brinell Hardness Test, Rockwell Hardness Test, Knoop Hardness Test and Vickers Hardness test (HARDNESS TESTING, n.d.). Before selecting one of these tests, it is recommended to consider the following: o The size of the sample o Surface of the material o Material type o Number of trials required o Accuracy and precision of result o Compatibility of materials with its mounting piece In the given lab experiment, conducted by Concordia University, for Winter semester of 2021, The Brinell Hardness test is used to determine the hardness of an indenter - 10mm steel ball, pressed against a steel and aluminum disc under a given force.

EQUIPMENT & PROCEDURE

EQUIPMENT:

Compression machine 10 mm steel ball- known as the indenter Microscope- Optical instrument to measure the diameter Finished surface of Steel and aluminum discs PROCEDURE: Using the illustration (Fig. 1) on page 3, proceed with the steps below. Step 1. Place the steel disc on the bottom plate illustrated in figure 1. In order to not distort the indentation upon pressure, ensure that there is a minimal contact between the steel disc and the indenter.

HB = (10070 𝑁) ∙ 1

5. The hardness for trial 1 is 94.72HB/10/10.07/

RESULTS FOR STEEL

The table below shows data gathered after calculating mean diameter, depth of indentation, area of indentation and Brinell Hardness test for trial 1, 2 and 3.

STEEL - BRINELL HARDNESS TEST RESULTS After compiling the data, the average Brinell number is 95.40 for steel.

RESULTS – CALCULATION FOR ALUMINUM

Note: Refer to appendices on page 14 to complete the calculation below A calculation sample is given for Trial 1 and have been used to calculate for trial 2 and 3.

1. Calculate mean diameter:

d = 3.6 𝑚𝑚+3.5 𝑚𝑚 2

= 3.55 𝑚𝑚

2. Calculate Depth of indentation:

𝑡 = 10−√102−3.552 = 0.325668497 ≈ 0.33 mm 2

3. Calculate area of indentation: A = 𝜋 ∙ 10 ∙ 0.33 ≈ 10.23 𝑚𝑚 2
4. Calculate Brinell Hardness number:

HB = (10070 𝑁) ∙ 1

5. The hardness for trial 1 is 50.70HB/10/5.09/

RESULTS FOR ALUMINUM

The table below shows data gathered after calculating mean diameter, depth of indentation, area of indentation and Brinell Hardness test for trial 1, 2 and 3.

Beside Brinell Hardness Test, there are three other types of test that can be useful in different setting. Each test is made to gather indentation of a material differently, for example, the Brinell Hardness Test is used when an indenter is pushed with a given force onto a plate for a certain time (in seconds) then using an optical measurement and Brinell’s equation, we solve for its hardness. The other test also known as The Rockwell Hardness test is widely used when testing material because it is easier to conduct and generally more accurate data-wise. In such setting, it is used when the indentation mark is too large or simply because the sample is bigger. On the other hand, the Knoop Hardness test is used mainly for smaller sample, and for indents that are closer to the edge. Similarly, an optical measurement is used to measure the indentation and successively calculated using its respective equation. Finally, the fourth test is Vickers hardness test. It is used in situation where the testing material is wider than most materials.

CONCLUSION

Despite having other tests to compute the hardness of a material, Brinell Hardness test was used in this lab. After calculating the hardness number, it is found that the average number for steel is 95.40 and that for aluminum is 50.31. Many factors could have challenged the results. As a possibility, a mis-calibration or unpolished surface could have led to this disagreement from its actual number, being 117 and 95 respectively. However, while keeping this aside, the objective of this lab was achieved, by using Brinell’s Hardness equation to calculate its hardness.

BIBLIOGRAPHY

Aldon Company. (n.d.). Aluminum vs steel. Retrieved from Aldon Company: HARDNESS TESTING. (n.d.). Retrieved from Struers Ensuring Certainty: Newage Hardness testing. (n.d.). Solution for material testing.