Reactive HVOF Spraying TiN-matrix Composite Coating and its Corrosion and Wear Resistance Properties

Jing Ma

Hebei University of Science and Technology

September 2009

Outline

1. Introduction

2. Experimental methods

3. Results and Discussion

4. Conclusion

5. Acknowledgement

6. Papers

Page3 of 19

1 Introduction

Titanium nitride (TiN) coatings have promising properties.

Preparation methods: physical vapour deposition (PVD) or chemical vapour deposition (CVD)

reactive thermal spraying: high deposition efficient

TiN coatings: Reactive Plasma Spraying

What is reactive thermal spraying?

Combination of Self-propagating High Temperature Synthesis and Thermal Spraying

Low cost;

In-situ composite coating

High density and bond strength

Short process

My works

TiN-matrix coating prepared by reactive HVOF (High Velocity Oxygen Fuel ) spraying

Research of its corrosion and wear resistance

2 Experimental Methods

Sample preparationSubstrate: Medium carbon steel (0.42-0.50wt.%C steel)

size : φ60×3mm

Process:

Ground ultrasonic cleaned sand blasted HVOF spraying

Measure methods

Corrosion test: CHI600C electrochemical analyzer

Wear test: MM type tester

phases and composition: XRD/EDS

Surface and cross-section morphologies: SEM/optical microscope

Fig.1 illustration of wear test equipment

3 Results and discussion

Fig.2 XRD analysis of HVOF TiN-matrix composite coating

The coating was consists of TiN, TiN0.3, Ti2O3 and TiO2

Fig.3 cross-section optical morphologies of HVOF spraying coatings

The coating was layer structure.thickness of coating reaches at about 300μm.

ElementSpectrum1

(at.%)Spectrum2

(at.%)Spectrum3

(at.%)

NK =>11 =<11 =<11

OK =>17 - =>16

TiK =<72 =>89=<73

The light phase may be Titanium nitrides (TiN and TiN0.3) and the dark phase may be the mixture phase of Titanium nitrides (TiN and TiN0.3) and Titanium oxides (Ti2O3 and TiO2).

-1 0 1 2 3 4 5 6 7 8

-7

-6

-5

-4

-3

-2

-1

0

D

CB

A

lgI

/A/c

m2

E /V (relative to Ag/AgCl electrode)

Carbon steel (1) Carbon steel (2) Carbon steel (3) HVOF TiN

2 coating (1)

HVOF TiN2 coating (2)

HVOF TiN2 coating (3)

Fig.4 polarization curves of HVOF spraying TiN-matrix composite coating in 3.5wt%NaCl solution

A board passivation zone

Tab.2 wear test result of HVOF TiN-matrix composite coating

load20kgf

(without coating)

20kgf(with

coating)

30kgf(with

coating)

75kgf(with

coating)

Mass loss/g

1.5814 0.0013 0.0036 0.0021

Wear coefficient

0.64 0.49 0.49 0.50

wear coefficient of coating at different loads maintained a constant value.

Fig.5 surface and cross section morphologies of TiN-matrix composite coating (30kgf ): (a) surface morphology; (b) cross section morphology

A

At light load: particles spalled.

(a) (b)

Fig.6 surface and cross section morphologies of TiN-matrix composite coating (75kgf ): (a) surface morphology; (b) cross section morphology

At high load: layer fatigue spallation

(a) (b)

two reactions in reactive spraying:

The overlap of reaction heat and HVOF flame make TiN melting and deposit as TiN-matrix composite coating.

)()(5.0)( 2 sTiNgNsTi

)()()( 22 sTiOgOsTi

11

22

33

The protective abilityof TiN-matrix composite coating prepared by reactive HVOF spraying in 3.5wt.%NaCl solution is excellent.

TiN-matrix composite coating about 300μm thickness was prepared by reactive HVOF spraying, which has layer structure.

The failure form of TiN-matrix composite coating at light loads is local spallation due to stress concentration while that at heavy loads is layer fatigue spallation.

4 Conclusion

5 Acknowledgement

Thanks for the open fund of State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology(KFJJ07-2).

Thanks for Dr. Li and committee of this conference!

6 papers

① Jing Ma ， Zhengping Mao ， Baode Sun ， Jun Wang. Microstructure and polarisation behaviour of TiN–TiB2 matrix coating prepared by reactive plasma

spraying. Materials Science and Technology, DOI 10.1179/174328409X443272 (SCI source).

② Zhengping Mao, Jing Ma, Baode Sun, Jun Wang. Properties of TiN-matrix coating deposited by reactive HVOF spraying. Journal of Coatings Technology and Research, 2009, 6 (2) 243–250 (SCI428JK) (EI20091612033022 )

③ Zhengping Mao, Jing Ma, Jun Wang, Baode Sun. Comparison of the coatings deposited using Ti and B4C powder by reactive plasma spraying in air and low

pressure. J Mater Sci (2009) 44:3265–3272 (SCI445GR)

④ Zhengping Mao, Jing Ma, Jun Wang, Baode Sun. Dry abrasion property of TiN-matrix coating deposited by reactive High Velocity Oxygen Fuel (HVOF) spraying. J. Coat. Technol. Res. DOI 10.1007/s11998-009-9180-6 (SCI source).

⑤ Zhengping Mao, Jing Ma, Jun Wang, Baode Sun. The effect of powder preparation method on the corrosion and mechanical properties of TiN-based coatings by reactive plasma spraying. Applied Surface Science, 2009, 255(6): 3784-3788(SCI387SO) (EI20090111825962 )