DTIC ADA604816: Nanocrystalline Co-P-SiC Electrocomposite Coating for Replacement of Hard Chrome

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by  Defense Technical Information Center

Nanocrystalline Co-P-SiC
Electrocomposite Coating for
Replacement of Hard Chrome
A.Datta , J.D.Carpenter and A. Kertesz
U.S. Chrome Corporation, Stratford, CT
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1. REPORT DATE 3. DATES COVERED
JAN 2006 2. REPORT TYPE 00-00-2006 to 00-00-2006
4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER
Nanocrystalline Co-P-SiC Electrocomposite Coating for Replacement of
5b. GRANT NUMBER
Hard Chrome
5c. PROGRAM ELEMENT NUMBER
6. AUTHOR(S) 5d. PROJECT NUMBER
5e. TASK NUMBER
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION
U.S. Chrome Corporation,175 Garfield Avenue,Stratford,CT,06615 REPORT NUMBER
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)
11. SPONSOR/MONITOR’S REPORT
NUMBER(S)
12. DISTRIBUTION/AVAILABILITY STATEMENT
Approved for public release; distribution unlimited
13. SUPPLEMENTARY NOTES
26th Replacement of Hard Chrome and Cadmium Plating Program Review Meeting, January 24-26, 2006,
San Diego, CA. Sponsored by SERDP/ESTCP.
14. ABSTRACT

15. SUBJECT TERMS
16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF
ABSTRACT OF PAGES RESPONSIBLE PERSON
a. REPORT b. ABSTRACT c. THIS PAGE Same as 18
unclassified unclassified unclassified Report (SAR)
Standard Form 298 (Rev. 8-98)
Prescribed by ANSI Std Z39-18
Outline
• Microstructure and X-ray diffraction
• Hardness characteristics
• Process control
• Corrosion resistance
• Wear and friction
• Application status
Microstructure
• Nanocrystaline Co-P matrix with 20-25 vol.%
of 2-5μm SiC particles
• SiC particles support contact load; very hard
SiC particles provide excellent wear
properties.
• Expected to have excellent tribological
performance based on those of a similar
Ni-SiC electrocomposite coating of
U.S.Chrome
Microstructure
Nanocrystalline Co- P matrix containing 2- 5μm SiC particles ;
No cracks or pits as found in hard chrome
X-ray diffraction results
Wt% P of the coating Coating structure
4.5 Nanocrystalline
5.6 Nanocrystalline
10.5 Amorphous
X-ray diffraction analysis performed by
Lambda Technologies, Cincinnati OH.
X-ray diffraction results
Coating with 4.5 wt.%P
Coating with 10.5 wt%P
Nanocrystalline
Amorphous
Grain size 48.4 nm
Hardness characteristics – As-plated
Co-P-SiC
As-Plated Hardness of Co-P-SiC vs. Wt%P in the Coating
800
700
Amorphous
600
0
0
1 500
N
H
V
, 400 Nanocrystalline
s
s
e
n 300
d
r
a
h 200
Hardness
100
0
0 5 10 15 20 25
Wt%P in the coating
Values of phosphorus content > 8 wt.%P were extrapolated from
Measured wt.%P vs. bath Phosphorus content linear regression
Hardness characteristics: 5.6 wt.%P
Co-P-SiC and Co-P, heat treated at 400˚C
Coating As - plated As heat As heat
treated at treated at
400˚C for 400˚C for
1.5hrs
24 hrs
Co - P 635 VHN 1000 VHN -
100 100
Co – P - SiC 653 VHN 1216 VHN 1060 VHN
100 100 100
Increase in hardness resulting from precipitation hardening is appreciably
Higher for Co-P-SiC compared to that of Co-P
Hardness characteristics: 5.6 wt.%P
Co-P-SiC and Co-P, heat treated at 204˚C
Coating As - plated As heat As heat
treated at treated at
204˚C for 204˚C for
1.5hrs
45 hrs
Co - P 635 VHN 688 VHN 630
100 100
Co – P - SiC 653 VHN 756 VHN 756 VHN
100 100 100
Low temperature heat treatment is necessary for certain alloys.
Some hardening is realized even at low temperature. Hardness increase is
higher for Co-P-SiC