Tensile Testing of Materials: Mechanical Properties of Metals

Introduction
Tensile testing is a basic material science and engineering test in which a sample piece is
placed in a tension until it fails. This testing is used to measure the different mechanical
properties of material.
Aim
This report aims to discuss about the various materials under tension and focused on finding
out the mechanical properties of metals.
Material Required
1. Bench top tensile tester
2. Vernier Calliper
3. 3 different pieces
 Stainless steel
 Aluminium and
 Galvanized steel
Procedure
 First, measure all the dimensions of all the specimens given
 Measure and mark the gauge length of all three specimens.
 Clamp properly testing piece on a bench top tensile tester
 Note all the data from the experiment.
Observation and difficulties
During the experiment the gauge length of metal pieces were marked by marker. It is
observed that stainless steel and the galvanized steel were broken from mid span whereas
aluminium was broken at the end. The stainless steel was elongated and needed more force as
the dimension was changed more compared to those of other two test pieces. There were
some difficulties in measuring after the fracture of the test pieces so measurements are
approximate.
Results and Discussion

Table: 1 Stainless Steel
Force(kN) ∆L Strain(mm/mm) Stress(MPa)
0.3 0.1 0.00095 7.2
0.1 0.5 0.0047 24
2.5 2 0.076 60
3.89 8 0.114 93.5
4.25 12 0.133 102
4.36 14 0.171 104
4.54 18 0.190 109
4.61 20 0.214 100
4.62 22.5 0.216 111
4.57 22.7 0.223 109
4.3 23.5 0.224 103
4.03 26.6 0.224 88
3.70 23.06 0.224 76
0 23.06(fail) 0.224 76
Dimension required for stainless steel
Total length = 105mm
Elongation = 126.3-105 = 21.3 mm
Thickness = 1.04 mm
Breadth = 40mm
Elastic Limit = 93.5 MPa, Yield Stress = 102 MPa, Ultimate tensile Stress = 111 MPa
Young’s Modulus = Stress
Strain (Upto elastic limit) = 93.5
0.114 = 820 MPa.
Table 2: Galvanized Steel

Force(kN) ∆L Strain(mm/mm) Stress(MPa)
0.15 0.6 0.0057 3.8
0.46 1.0 0.0095 25.5
0.8 1.2 0.0114 20.4
1.15 1.4 0.0133 29.3
1.4 1.5 0.0142 35.71
1.57 1.7 0.016 40
1.65 4.5 0.0428 42
1.7 5.70 0.0542 43.3
1.74 9.3 0.0885 44.3
1.72 10.1 0.0961 43.8
1.54 11.5 0.1095 39.2
1.2 11.8 0.1123 30.6
0 11.8(fail) 0.112 0
Dimension
Thickness = 0.98mm
Width = 40 mm
Total length L = 105 mm
Elongation = 115-105 = 2.62mm
Elastic Limit = 25 MPa, Yield Stress = 25.5 MPa, Ultimate strength = 44.3 MPa
Young’s Modulus = Stress
Strain (Upto elastic limit) = 25.5
0.0095 = 2.684 GPa.