MSE 201 – Laboratory IThe University of Tennessee

Materials Science and Engineering

Kurt Johanns

MSE 201 - Laboratory I

Mechanical Properties of Metals

MSE 201 – Laboratory IThe University of Tennessee

Lab Report Guidelines

Hardness Testing

Tensile Testing

Charpy Impact Testing

Outline

MSE 201 – Laboratory IThe University of Tennessee

Lab Report Guidelines

Due One Week After Data is Posted

Email or Mail Box 4th Floor

Attach Calculations

Any Format You Like

Develop Thoughts and Answer Questions in Complete Sentences

MSE 201 – Laboratory IThe University of Tennessee

Safety

Wear Protective Clothing

Watch Your Surroundings

MSE 201 – Laboratory IThe University of Tennessee

Mechanical Properties

MSE 201 – Laboratory IThe University of Tennessee

Materials

1. As Received (Cold Rolled) 1018 Carbon Steel:

10xx = Plain Carbon Steel

1018 = 0.18 wt% Carbon

Contains Trace Mn, P, and S

2. Annealed 1018 Carbon Steel

870 Degrees C for 2 hrs

Cooled Slowly with Furnace for 24 hrs

MSE 201 – Laboratory IThe University of Tennessee

Tensile Testing

Known Dimensions:

Gauge Diameter (in.)

Gauge Length (in.)

What is Measured:

Applied Load (lbs)

Elongation (in.)

MSE 201 – Laboratory IThe University of Tennessee

Stress vs Strain

E

UTS

Calculated Properties:

Young’s Modulus

UTS

0.2% Yield Stress

Failure Stress

% Elongation

Ductility

Toughness

“Cold Rolled”

MSE 201 – Laboratory IThe University of Tennessee

Hardness Testing

Hardness: The Measure of a Material’s Resistance to Deformation by Surface Indentation or Abrasion.

Adjectives: “Hard” or “Soft”

Hardness Tests:

Vickers and Knoop Hardness – Diamond Pyramidal

Mohs Hardness Scale - Scratches

Rockwell Hardness – Spherical Indents

MSE 201 – Laboratory IThe University of Tennessee

Rockwell Hardness

HRB and HRF Scales:

HRB – 1/16 Diameter Steel Ball – 100kgf

Cu and Al Alloys, Soft Steels

HRF – 1/16 Diameter Steel Ball – 60kgf

Annealed Alloys and Steels

The Resulting Hardness Number Is Determined From the Indent Depth of Penetration

MSE 201 – Laboratory IThe University of Tennessee

Hardness Testing

Procedure:

Clean Surface Thoroughly

Sample Thickness > 10x Indent

Indents 3x-5x Indent Diameter Apart

Correct for Surface Curvature (ASTM E-18)

Use Superficial Scales for Thin Samples

MSE 201 – Laboratory IThe University of Tennessee

Rockwell Hardness

Minor Load Displacement

Major Load Displacement

RH is a Function of

MSE 201 – Laboratory IThe University of Tennessee

Rockwell Hardness

Flat Surface

Flat Surface

ASTM E-18 for Correction

MSE 201 – Laboratory IThe University of Tennessee

Charpy Impact Testing

MSE 201 – Laboratory IThe University of Tennessee

Brittle to Ductile Transition

Impact

Energy

Temperature

Transition

Range

MSE 201 – Laboratory IThe University of Tennessee

Fracture Surfaces

Ductile Brittle

MSE 201 – Laboratory IThe University of Tennessee

Charpy Impact Testing

Impact Conditions:

Extreme Conditions

High Strain Rate

Triaxial Stress States

ASTM Standard E-23

5 cm

1 cm

MSE 201 – Laboratory IThe University of Tennessee

Charpy Impact Testing

h = 0

At Impact

h = h1

h = h2

MSE 201 – Laboratory IThe University of Tennessee

Charpy Impact Testing

Five Temperature Ranges:

Liquid Nitrogen (-196 deg C)

Dry Ice (-78 deg C)

Ice Water (0 deg C)

Room Temp (25 deg C)

Boiling Water (100 deg C)