Hardness Testing Lab Report
1. INTRODUCTION
The purpose of the following experiments is to study the hardness of different types of materials, and to understand the significance of this property in materials. The materials and the aforesaid property have significant use in civil engineering.
Hardness is defined as a measure of a material’s resistance to localised plastic deformation (i.e. small dents or scratches).
As said above, a variety of metal alloys were used in the experiments to understand how each of these metals is characterised as a hard metal and to compare the hardness of different metal alloys. A study of how the molecular structure and the carbon content affects the hardness of each metal alloy used is also done during the course of the experiment.
Three different tests are used, namely: (i) Vicker’s Hardness test (ii) Rockwell Hardness test (iii) Brinell Hardness test
A further experiment, known as the Charpy Impact Test is conducted to study the toughness of some specimens of steel. Toughness is the measure of the ability of a material to absorb energy up to fracture. It has been discovered that the larger the area under a material’s stress-strain curve, the tougher it is. Therefore a more ductile material is tougher. An impact test is used to ascertain the fracture characteristics of the material, and it merely offers a relative sense of a material’s toughness.
2. APPARATUS (i) Vicker’s Hardness Tester is shown in Figure 1.
Figure 1 (ii) Rockwell Hardness Tester, as shown in Figure 2.
Figure 2 (iii) Brinell’s Hardness Tester, as shown in Figure 3.
Figure 3 (iv) Mild steel specimen (v) Carbon steel specimen (vi) High carbon steel specimen (vii) ASSAB steel specimen
3. TESTS
4.1 VICKER’S HARDNESS TEST
4.2.1 Experimental Procedure
i. We used a mild steel specimen and a carbon steel specimen for this experiment. ii. We placed the specimen on the stand under the lens. iii. We then ensured that the image of
The purpose of the following experiments is to study the hardness of different types of materials, and to understand the significance of this property in materials. The materials and the aforesaid property have significant use in civil engineering.
Hardness is defined as a measure of a material’s resistance to localised plastic deformation (i.e. small dents or scratches).
As said above, a variety of metal alloys were used in the experiments to understand how each of these metals is characterised as a hard metal and to compare the hardness of different metal alloys. A study of how the molecular structure and the carbon content affects the hardness of each metal alloy used is also done during the course of the experiment.
Three different tests are used, namely: (i) Vicker’s Hardness test (ii) Rockwell Hardness test (iii) Brinell Hardness test
A further experiment, known as the Charpy Impact Test is conducted to study the toughness of some specimens of steel. Toughness is the measure of the ability of a material to absorb energy up to fracture. It has been discovered that the larger the area under a material’s stress-strain curve, the tougher it is. Therefore a more ductile material is tougher. An impact test is used to ascertain the fracture characteristics of the material, and it merely offers a relative sense of a material’s toughness.
2. APPARATUS (i) Vicker’s Hardness Tester is shown in Figure 1.
Figure 1 (ii) Rockwell Hardness Tester, as shown in Figure 2.
Figure 2 (iii) Brinell’s Hardness Tester, as shown in Figure 3.
Figure 3 (iv) Mild steel specimen (v) Carbon steel specimen (vi) High carbon steel specimen (vii) ASSAB steel specimen
3. TESTS
4.1 VICKER’S HARDNESS TEST
4.2.1 Experimental Procedure
i. We used a mild steel specimen and a carbon steel specimen for this experiment. ii. We placed the specimen on the stand under the lens. iii. We then ensured that the image of
References: William D. Callister, Jr. (2003), Materials Science and Engineering: An Introduction, (6th ed.), New York: Wiley, p137.