Hardness Testing
Lab 1
Moriah Ausherman
E882U679
Kunza Arifa
ME-251-10959
Thursday 3:30
Experiment Date- 8/31/2017
Due Date- 9/7/2017 Introduction: The purpose of this lab is to ascertain the hardness of two different materials. One material is aluminum the other will be determined through testing. Hardness is defined as a material’s ability to resist plastic deformation by indentation. Harder objects are more likely to resist deformation. The results of a hardness test will be important for engineers to determine what material will work best for a project. The material will need to hold up to any stress put on it and be able to work for a long period of time. A high score on the test done in this lab means a material that …show more content…
Applying a minor load of 10 kg to the material. When the dial is set to zero, apply the major load by pressing start. Record the results and repeat with a new sample.
Results: Hardness # (HRB) 1st Reading 2nd Reading 3rd Reading Average % Error
Aluminum Specimen 83.8 83.8 83.1 83.566667 1.71%
Unknown Specimen 102.4 101.4 101.7 101.83333 ---
Analysis: The Rockwell Hardness Test B produced in very consistent results. The first sample, aluminum, gave an average hardness of 83.567 which is in the aluminum hardness range of 50-96. Matweb had an average value listed as 82.6. This gives a percent error at 1.171% which is low for the usage of an average value. The second sample, unknown, gave an average hardness of 101.833. The top candidates, due to the HRB scores being the closest to the experiment are listed below,
1. Cobalt Alloy 80.0-116
2. Copper-Cobalt-Beryllium alloy, UNS C17500 98.0-103
3. Stainless Steel 37.0-130
4. Beryllium Copper, UNS C17000, TD04 Temper Strip 96.0-102
5. Medium Carbon Steel 71.0-112
6. AlSl 800 Steel 102
7. Tungsten Alloy 32.0-110
8. Silver Alloy 35.0-102
9. Materion Brush 60 ¾ HT 98.0-103
10. Chromium-Copper UNS C17600 …show more content…
AlSl 800 Steel has an HRB score of 102, which is almost exactly what the results provided. This gives a percent error of 0.196%. The type of material also works well on the B scale. This is stated on slide 19 of the Hardness Test Powerpoint, “Soft materials such as copper alloys, soft steel, and aluminum alloys.” The material is unlikely to be aluminum due to the difference in HRB score. It is also unlikely to be a copper alloy due to the lack of copper tint. Based on the HRB score and type of test used, the unknown material was most likely a soft steel.
Conclusion: In this lab, the Rockwell Hardness Test was used to determine the true hardness score of aluminum and what the unknown sample was. By putting the sample under a large amount of pressure, the machine will determine how susceptible to damage that material is. Based on the depth of the indent created by the machine, a number will be given. The higher the number, the harder the material is. So the unknown material that was tested is harder than aluminum. Which is consistent with our unknown being steel. Steel is generally harder and more likely to resist deformation than
Lab 1
Moriah Ausherman
E882U679
Kunza Arifa
ME-251-10959
Thursday 3:30
Experiment Date- 8/31/2017
Due Date- 9/7/2017 Introduction: The purpose of this lab is to ascertain the hardness of two different materials. One material is aluminum the other will be determined through testing. Hardness is defined as a material’s ability to resist plastic deformation by indentation. Harder objects are more likely to resist deformation. The results of a hardness test will be important for engineers to determine what material will work best for a project. The material will need to hold up to any stress put on it and be able to work for a long period of time. A high score on the test done in this lab means a material that …show more content…
Applying a minor load of 10 kg to the material. When the dial is set to zero, apply the major load by pressing start. Record the results and repeat with a new sample.
Results: Hardness # (HRB) 1st Reading 2nd Reading 3rd Reading Average % Error
Aluminum Specimen 83.8 83.8 83.1 83.566667 1.71%
Unknown Specimen 102.4 101.4 101.7 101.83333 ---
Analysis: The Rockwell Hardness Test B produced in very consistent results. The first sample, aluminum, gave an average hardness of 83.567 which is in the aluminum hardness range of 50-96. Matweb had an average value listed as 82.6. This gives a percent error at 1.171% which is low for the usage of an average value. The second sample, unknown, gave an average hardness of 101.833. The top candidates, due to the HRB scores being the closest to the experiment are listed below,
1. Cobalt Alloy 80.0-116
2. Copper-Cobalt-Beryllium alloy, UNS C17500 98.0-103
3. Stainless Steel 37.0-130
4. Beryllium Copper, UNS C17000, TD04 Temper Strip 96.0-102
5. Medium Carbon Steel 71.0-112
6. AlSl 800 Steel 102
7. Tungsten Alloy 32.0-110
8. Silver Alloy 35.0-102
9. Materion Brush 60 ¾ HT 98.0-103
10. Chromium-Copper UNS C17600 …show more content…
AlSl 800 Steel has an HRB score of 102, which is almost exactly what the results provided. This gives a percent error of 0.196%. The type of material also works well on the B scale. This is stated on slide 19 of the Hardness Test Powerpoint, “Soft materials such as copper alloys, soft steel, and aluminum alloys.” The material is unlikely to be aluminum due to the difference in HRB score. It is also unlikely to be a copper alloy due to the lack of copper tint. Based on the HRB score and type of test used, the unknown material was most likely a soft steel.
Conclusion: In this lab, the Rockwell Hardness Test was used to determine the true hardness score of aluminum and what the unknown sample was. By putting the sample under a large amount of pressure, the machine will determine how susceptible to damage that material is. Based on the depth of the indent created by the machine, a number will be given. The higher the number, the harder the material is. So the unknown material that was tested is harder than aluminum. Which is consistent with our unknown being steel. Steel is generally harder and more likely to resist deformation than