Investigation of Mechanical and Tribological

Properties of Materials in Micro and Nano Scale

with Nano-Indenter and SPM

Surface Science

&

Nano-Tribology Lab

MTS Nano Indenter XP

Source: www.MTS.com

Digital Instruments NanoScope IIIa SPM

Source: www.DI.com

Adhesion Failure of Ink on Plastic Films

Adhesion Strength Test: The Nano Indenter (MTS) with a conical-

shaped diamond tip (90, radius: 1m) is used to scrape the surfaces of the

samples under an increasing normal force The critical forces, at which

the interface failed and the ink was peeled off the plastic film, reflects the

adhesive strength.

Adhesion: a measure of the strength of bonds between the ink and

plastic substrate through the interface.

Different configurations of adhesion failure

I

II

III

IV

V

(a) 2-D color-scaled topographic image of a scratch made under an increasing force from 2.9mN to 3.1mN at the surface of an ink sample.(b) Profile along the bottom of the ditch.(c) 3-D view of the topographic image.(d) Lateral force image taken simultaneously with the topographic image.

A

ac d

b

SPM analysis of adhesion failure

Hard-coated Polycarbonate Systems

Table: Critical force for transition between damage types.

Sample Mar

RoughTrough

RoughTrough

Crack

Crack

Delamination

Delamination

Chip

A 25mN 35mN 55mN

A + Plasma 10mN 30mN 50mN 60mN

B 28mN 42mN

B + Plasma 15mN 25mN

* For sample A and A + Plasma, Delamination and Chipping co-occur most of times, and hardly be

distinguished in two steps clearly.

* For sample B and B + Plasma, no Delamination and Chipping were observed up to a constant force of 150mN.

SPM images of Mar and rough trough

Sample A after scratch at 10mN and 20mNScan Size: 80m 80m, Z-range: 400nm

Sample A after scratch at 30mNScan Size: 80m 80m, Z-range: 1000nm

SPM images of cracking and delamination

Sample A after scratch at 40mN and 50mNScan Size: 80m 80m, Z-range: 4000nm

Sample A after scratch at 60mNScan Size: 80m 80m, Z-range: 4000nm

Mold-In-Color Plastic Panels

A1 A2

Flow

direction

A3

B1 B2 B3

C1 C2 C31

23

C

B

A

0

5

10

15

20

25

30

35

Har

dn

ess

(MP

a)

C

B

A

Hardness of the plastic deviate little on different locations of the panel.

SPM phase images of sample A

Before washingScan Size: 5m 5m, Z-range: 45

After washing with IPAScan Size: 5m 5m, Z-range: 45

SPM phase images of sample B

Before washingScan Size: 5m 5m, Z-range: 45

After being rubbed with cottonScan Size: 5m 5m, Z-range: 45

Brass

Brass

Soft Coating

Hard Coating

Brass

8m Ni

0.25m ZrNCoating

0.25m Cr

Organic/Inorganic coatings deposited on brass

Brass substrate

ZrN/Cr/Ni/Brass (traditional coatings)

Organic/Inorganic Coatings for Hardware

M-1 (500 mm) M-3 (500 mm)M-2 (500 mm)

M-1 (z: 500 nm/div) M-2 (z: 500 nm/div) M-3 (z: 500 nm/div)

Damage patterns in the real applications

Fatigue in rubber rings

0

1

2

3

4

0 4000 8000 12000

Displacement (nm)

Load

(mN

)

A

B

-2

0

2

4

6

8

10

12

0 4000 8000 12000 16000

Displacement (nm)

ABC

EASTERN MICHIGAN UNIVERSITY

NANO TRIBLOGY LABORATORY