Advanced Coating Produced by ElectrophoreticDeposition

By PhD student Iman AdnanSupervised by

Prof. Dr. Mohammed J. Al-Tameemi Prfo.Dr. Sami I. Al-Rubaiey

 

Sample Preparations-The substrate material used in this study was 316L stainless steel alloy. The samples

were cut in to dimension of (30*15*0.2) mm.-These samples were ultrasonically cleaned type (BANDELIN SONOREX RK 100, made in

Germany), with acetone for 20 min. and then dried with nitrogen gas.- The samples were weighted before and after coating process using a 4 digit balance

with 0.01mg resolution (mettle AE163, Leicester, UK).- The weight of coating layer is equal to the weight of sample after coating minus the

weight of sample before coating in mg.2. Solution Preparations1. The suspension was prepared by dissolving chitosan was purchased from Sigma-

Aldrich in 1% acetic acid (>98% purity), and then used for the preparation of suspension for EPD.

2. Different amount from YSZ and HA were used.3. Three solvents were used to prepare suspension. 4. The suspension was stirred in magnetic stirrer for 24 hr., and then in the ultrasonic

stirrer for 20 min.5. The PH of the suspensions was measured by the PH-electrode. 

Experimental work and Procedure

1. A316LSS alloy were used as anode and cathode electrodes.

2. The electrodes were washed with acetone and then dried.

3. The coating process was carried out at room temperature from 100 ml. of the suspension.

4. Only (20*15) mm of substrate was exposed to deposition.

5. EPD was performed at different volts using a laboratory DC-Power supply.

6. EPD was performed at different deposit time.

Experimental procedure for EPD

7. The distance between the electrodes was 10mm.

8. YSZ-Chitosan, HA-Chitosan, and TSZ-Chitosan-HA composite were deposited on 316lss alloy by EPD.

9. The samples were dried in air atmosphere after the complete of EPD process.

10-EPD was performed three times for each condition and the average of deposition was calculated.

   

 Fig .4

Experimental procedure for EPD

Experimental procedure for EPD

1. Scanning electron microscopy (SEM).

 The SEM (JEOL, JSM 5410, Japan) was used to demonstrate the surface morphology of the representative samples of each coating condition and examined using different magnifications. Before SEM the coated surface were sputter coated with chromium to prevent electrostatic charging.

 

Characterization of the coating

The phase purity was tested by x- ray diffraction on D8 ADVANCE X-RAY diffractometer (Brucker) in 2θ range of 20-80˚ with cu k α radiation step size of 0.014 with 1s per step was used

2.X-Ray

Spectroscopic analysis was carried out using Fourier transform infrared (FTIR) spectroscopy (Nicolet 6700 Thermo Scientific, Waltham, MA, USA) measurements were performed to record spectra of the coated samples in the wave number range of 400–4000 cm-1.

The procedure for preparing the sample for FTIR –test was done by the following steps:-

1-The deposited powder was scrapped from 316LSS substrate and then 0.002g from this powder was taken.

2-0.2g from KBr (potassium bromed) was added to the coating powder.

3-The mixture was put in to circle die and then pressed in to the form of pellet.

3. FTIR- Test.

  

4. Contact- Angle.

•The wet ability between the substrate and coating was measure using contact angle device type KRUSS DSA30, Hamburg2009, using software DSA4 for Drop Shape Analysis

  

4. Contact- Angle.

Adhesion between coatings and substrates was tested by Elcometer 107 cross hatch cutter (Great Britain). The composites coating were tested according to ASTM D3359-B standard, as shown in Fig.10.

Adhesion-Test

Zeta potential and electrophoretic mobility were measured by laser Doppler velocimetry (LDV) technique, using Zetasizernano ZS equipment (Malvern Instruments, UK).

6. Zeta-Potential

Corrosion resistance of metal substrates used in biological environments is an important issue that gives an indication of the biocompatibility of the materials, as corrosion products must be minimized. Polarization curves for YPZ-chitosan-

HA, YPZ-chitosan and bare stainless steel substrate (SS) are shown in Figure (4). The results show a lower corrosion current for all coated systems compared with the uncoated metallic substrate, being proof of the corrosion protective properties of these coatings

7. Corrosion Behavior