LABORATORY

MATERIALS ENGINEERING I

pROFESSOR: / Pre-report: / 20%
INSTRUCTOR: / QUIZ: / 20%
NAME: / REPORT: / 40%
CLASS’ HOUR & DAY: / Total: / 100%
LAB GROUP:
TUITION NUMBER:

DETERMINATION OF MECHANICAL PROPERTIES

OF ENGINEERING MATERIALS

0. PRE-REPORT

  1. Do a synthesis of the previous lecture with a maximum extension of one hand written sheet.
  2. What is the relationship between the mechanical properties of materials and their microstructure?
  3. Which standard is used for the tensile stress test and which are its parameters?

1. OBJECTIVES

a)The student will learn the use and application of both the universal testing machine and the durometer.

b)The student will identify different types of materials as well as their mechanical properties, through the use and knowledge of both destructive and non-destructive tests.

c)The student will learn to recognize different regions on the strain-stress curve for determining the mechanical properties.

2. MATERIAL / EQUIPMENT

  • Three test tubes of different materials for tensile stress test.
  • One sample of tempered steel.
  • Rockwellhardness tester.
  • Universal testing machine.

3. PROCEDURE

  1. The instructor will explain the operation of both the universal testing machine and the Rockwell hardness tester.
  2. The students will proceed to perform tensile stress tests on the three test tubes provided by the instructor.
  3. The students will perform Rockwell hardness tests on the three test tubes provided by the instructor.
  4. The students will analyze the results obtained and will fill the questions in the report section.

4. REPORT

a.Experimental results
  1. Experimental results of the tensile stress test and the hardness test.

Property / Material 1:
CARBON STEEL
1045 / Material 2:

ALUMINUM

/ Material 3:
NYLAMID / Material 4:
CARBON STEEL
1045 TEMP. / Units
Young’s modulus
Yield Strenght
Ultimate Tensile Strenght
Fracture Strenght
%Elongation
% Reduction in area
Hardness (specify scale)
  1. Append the strain-stress graphs (using the stresses obtained with the tensile stress test.)
b.Questions
  1. Which of the materials used is the most ductile and which is your indicator?
  2. Which of the materials used is the most rigid and which is your indicator?
  3. Why is it preferable to use the strain-stress graph to the real tensile stress?
  4. Obtain the equivalents of the measured hardnesses in Brinell scale.
  5. From the tensile stress tests performed, what noticeable differences are observable among the mechanical properties of both metals and polymers?

Photos / Usage description
5. CONCLUSIONS

1