Diamond Precision Diagnostics

Penetration
Dynamics.

Calculate HV standardized numbers. Engage live optic imaging missions to validate surface toughness scorecard credits.

ENTER LAB VIRTUAL EXPORT REPORT PDF

LAB MANUAL (EXP 6: HARDNESS TEST)

Use this as your report structure (and check the rubric)

1.0 Objectives

  • Identify hardness as resistance to localized plastic deformation (indentation).
  • Perform Vickers hardness testing using the correct load, dwell time, and measurement method.
  • Record indentation diagonals, compute HV, and compare hardness across specimens.
  • Discuss factors affecting hardness results (surface preparation, load, dwell, operator reading, material microstructure).

2.0 Apparatus & Safety

Minimum apparatus (adjust to your lab):

  • Vickers hardness tester with diamond pyramid indenter (136°).
  • Standard test blocks (verification), microscope/optical system for diagonal reading.
  • Specimens (at least 2 materials), polishing papers/cloth, ethanol/cleaning tissue.
  • PPE: safety glasses; gloves when handling solvents.

Safety checkpoints:

  • Keep fingers away from indenter/anvil during loading.
  • Clean specimen (no grit) before placing to avoid scratching optics/anvil.
  • Use the microscope carefully; do not force focusing knobs.

3.0 Theory (Vickers)

Hardness is commonly defined as resistance to localized plastic deformation. Indentation methods infer hardness by pressing a known indenter geometry into the surface under a known load for a controlled dwell time.

In the Vickers test, a diamond pyramid indenter is used. After unloading, the two diagonals of the square indentation are measured and averaged to estimate the indentation area.

HV = 1.854 × F d2

F = applied load (kgf), d = average diagonal (mm), HV in kgf/mm²

Common Hardness Number Equations (Reference)

Brinell (HB)
HB = 2P πD (D − √(D2 − d2))
P = load, D = ball diameter, d = indentation diameter
Vickers (HV)
HV = 1.854P d2
P = load, d = average diagonal
Knoop (HK)
HK = 14.2P l2
P = load, l = long diagonal

Note: Use the equation required by your tester/method. This experiment focuses on Vickers hardness (HV).

Reference Figures (Softcopy Manual)

Reference Figure A: Indentation hardness tests overview (Brinell, Vickers, Knoop, Rockwell)
Figure A: Overview of common indentation hardness tests and equations (illustrative).
Reference Figure B: Hardness scales comparison with typical material ranges
Figure B: Illustrative comparison of hardness scales and typical material ranges (not-to-scale guide).

4.0 Procedure (Recommended)

4.1 Specimens Provided

Students will be provided specimen samples: Steel, Copper, and Aluminum.

4.2 Position and Focus

To perform the test, position the specimen on the stage and move it under the microscope. Focus until the surface is clear.

4.3 Select Test Location (X–Y Stage)

Using the X–Y coordinate micrometer screws mounted on the stage, shift the sample and select the area to be tested (avoid edges, scratches, and prior indents).

4.4 Apply Load

Select a test load of 0.1 kg, 0.5 kg, and 1.0 kg (100 g, 500 g, and 1000 g), then press Run to perform the indentation. Record the load and dwell time used.

4.5 Measure Indentation Diagonal(s)

Measure the diagonal(s) of the impression using the length adjustment. The impression seen through the screen is a square with diagonals running between the corners (as shown in Figure 3).

d d

Figure 3: Impression made by Vickers indenter (measure both diagonals)

Compute average diagonal: d = (d1 + d2) / 2, then compute HV using HV = (1.854 × F) / d2.

5.0 Results Template (Copy Into Report)

Record at least 3 readings per specimen:

Specimen Load F (kgf) Dwell (s) d1 (mm) d2 (mm) d (mm) HV
A (Trial 1)
A (Trial 2)
A (Trial 3)

Minimum calculations to show (in your own words):

  • Compute d from d1 and d2 (show at least 1 full worked example).
  • Compute HV using HV = (1.854 × F) / d2 (show substitution and unit consistency).
  • Compute mean hardness per specimen and compare trends.
5.1 Required Attachment

Attach your results and discuss all relevant information related to hardness of materials tested.

5.2 Plot Required Graph

Using the data from each sample, plot a graph of hardness value (HV) versus loading (g). Discuss the results obtained and compare Steel vs Copper vs Aluminum.

5.3 Determine HV at 800 g

Using the plotted graph, determine the hardness value for each sample at a loading of 800 g. If you only tested 500 g and 1000 g, estimate the value by interpolation between those points (show your working).

6.0 Discussion Prompts

  • Compare hardness values between specimens. What material or treatment differences could explain the trend?
  • How do load and dwell time influence indentation size and measurement uncertainty?
  • List at least 3 sources of experimental error and propose mitigation steps.
  • Relate hardness to strength or wear performance (briefly, with references if used).

Report reminder

Use the rubric in the next section; Results & Calculations and Discussion are weighted (×2).

Quick Quiz (5 Questions)

Answer all questions, then grade to check understanding.

Q1

What indenter geometry is used in the Vickers hardness test?

Q2

Which equation is commonly used for Vickers hardness (HV)?

Q3

If the measured diagonals are d1 and d2, how do you find the value of d used in the HV equation?

Q4

In this experiment, students test loads of 0.1 kg, 0.5 kg, and 1.0 kg. What are these loads in grams?

Q5

Your report requires HV vs loading (g) graphs and HV at 800 g. If you only measured at 500 g and 1000 g, the most appropriate method to estimate HV at 800 g is:

AUTHENTICATED LAB SIMULATIONS

Interactive scorecards will sync to legitimate university rosters

SIM 1: LOAD PRESSURE WINDOW 0 kgf
Target
SIM 2: CRATER forensic ID Points: 0
SIM 3: Live Optic SNAP Challenge

PROFESSIONAL Performance SCORING BAND

Item Score 5 (Excellent 9-10) Score 4 (Good 7-8) Score 3 (Satisfactory 5-6) Score 2 (Poor 3-4) Score 1 (Very Poor 0-2)
1. Appearance All sections sequence perfectly; layout clean; minor slips only; custom typed cover; single PDF. Good formatting; occasional issues; one detail missing; bound. Rough formatting; uneven organisation; 2 details missing; stapled. Messy; torn inserts; >2 details missing; poorly stapled. Meets “Poor” or absent.
2. Objectives Rephrased clearly; links to prior knowledge; integrates external sources. Phrasing good; partial paraphrasing; prior knowledge present. Loosely stated; heavy manual reliance; some prior knowledge. Unclear; minimal prior knowledge; copied verbatim. Content absent.
3. Apparatus Complete list + diagrams; numbered steps (own words); safety photo included. Vital items; paraphrased; safety report (no photo). Partial list; steps unclear/copied; no diagrams. Missing equipment; procedure unusable. Content absent.
4. Results & Calcs (×2) Accurate data showing trends; figures labelled/captioned; consistent units; full calc walkthroughs. Trends less obvious; figures labelled; minor calc gaps. Data missing/disorganised; inconsistent labels; calc errors. Unreliable data; poor figures; calcs absent. Content absent.
5. Discussion (×2) Answers all Qs; explains trends/theory link; analyses errors & mitigation. Misses 1 Q; minor gaps; notes errors. Misses 2 Qs; partial understanding; shallow error mention. Misses multiple Qs; incorrect interpretation. Content absent.
6. Conclusions Summarises data; validates objectives; addresses errors & improvements. Missing one “Excellent” element. Missing two elements. Missing three+ elements. No conclusion.
7. References >9 sources; >30% recent; correct format. 6-8 sources; manual formatting. 3-5 sources; mixed formatting. 1-2 sources; format ignored. No references.
ATTENDANCE RULE: Absent = 0% Lab conducted but no report = Max 10%

Validated Performance Center

Record your observations. Your simulation score is shown on the right. Export a formatted PDF summary for submission.

Simulation Score (Points)
0
Recorded points for this activity