Nic AllenJeff Laun

BEL AIR MASS FINISHING MQP

Study surfaces produced by mass finishing

Understand the basic mechanisms we have determined the normal forces between a surface and a sample mass finishing media

Study how the surface produced by mass finishing eff ects the shininess of the surface.

OBJECTIVE

BEL AIR FMSL 22CENTRIFUGAL DISC FINISHER

Al 6061-T6

Polished Al Surfaces to a mirror.

Obtained a Vickers Hardness value of the surface

Mass Finished with abrasive media for 30 s.

Measured the depths of the scratches

Calculated the normal force

EXPERIMENT, SCRATCH DEBTHS

POLISHED SURFACE (100X)

EXAMPLE SCRATCH (50X)

EQUATION USED FOR FORCE CALC

HV= Vickers HardnessF= Force (Newtons)A= Area

Parameter Mean Value Standard Deviation

Scratch Depth 0.399 µm 0.180 µm

Scratch Width 5.396 µm 1.337 µm

Scratch Cross-Sectional Area

2.204 µm2 0.790 µm2

Vickers Hardness 124.0 HV10g6.555 HV10g

Normal Force 19.09 mN -

RESULTS

Normal Force = 0.07 ounces

OLYMPUS USPM-RU IIIMICRO SPECTROPHOTOMETER

Turned Al 6061-T6 @ 0.05mm/rev @ 2000 rpm (~3.94 in/min)

Took measurements of surface on confocal microscope

Mass Finished for 30s, 1 min, 4min, 10 min, 30 min, & 60 min taking measurements of the surface at each time interval

Also, measurements were taken with the spectrophotometer

EXPERIMENT, REFLECTIVITY

IMAGES OF SURFACES (20X)

Initial 30s 1 min

4 min 10 min 1 hr.

SPECTROPHOTOMETER RESULTS (INITIAL)

350 400 450 500 550 600 650 700 750 8000

10

20

30

40

50

60

Percentage of LIght Returned vs. Wavelength

Series1

Wavelength, nm

Refl

ecti

vit

y,

%

SPECTROPHOTOMETER RESULTS (1 HR)

350 400 450 500 550 600 650 700 750 8000

5

10

15

20

25

Percentage of Light Returned vs. Wavelength

Series1

Wavelength, nm

Perc

enta

ge o

f Lgit

h R

etu

rned

ROUGHNESS VS. TIME

0 10 20 30 40 50 60 700

0.1

0.2

0.3

0.4

0.5

0.6

Roughness vs. Time in Finisher

Time, min

Ra,

µm

2

RELATIVE AREA VS. SCALE FOR ALL TIMES100X OBJECTIVE

REFLECTIVITY VS. TIME

0 10 20 30 40 50 6015

20

25

30

35

40

Reflectivity (405 nm) vs. Time

Time, min

Refl

ecti

vit

y,

%

RELATIVE AREA VS. REFLECTIVITY

0.995 1 1.005 1.01 1.015 1.02 1.025 1.03 1.035 1.040

5

10

15

20

25

30

35

40

f(x) = − 384.506259924448 x + 418.828154411647R² = 0.870142559702443

Relative Area (2 µm2) vs. Reflectivity (405 nm)

Relative Area, µm2

Refl

ecti

vit

y,

%

CORRELATION OF REFLECTIVITY AND AREA SCALE (380NM)

0.001 0.01 0.1 1 10 100 1000 100000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Reflectivity - 380 nm vs. Relative Area

Scale, µm2

R2

CORRELATION OF REFLECTIVITY AND AREA SCALE (405 NM)

0.001 0.01 0.1 1 10 100 1000 100000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Reflectivity - 405 nm vs. Relative Area

Scale, µm2

R2

CORRELATION OF REFLECTIVITY AND AREA SCALE (515 NM)

0.001 0.01 0.1 1 10 100 1000 100000.000.100.200.300.400.500.600.700.800.901.00

Reflectivity - 515 nm vs. Relative Area

Scale, µm2

R2

3D GRAPH OF AREA SCALE, WAVELENGTH, AND CORRELATION

Best correlations found at 405 nm and a scale of ~2μm2

This Wavelength of light is the same used in the confocal microscope’s laser Unsure of significance of this finding

Correlations drop off significantly after ~450 nm and again at ~600 nm

RESULTS