Volume 05 - Surface Engineering Part 10 ppsx

Metallurgical factors
Anodizing Conditions.
Fig. 8
Effect of anodizing conditions on specular reflectance of chemically brightened aluminum. Data are for a
5 μm (0.2 mil) anodic coating on 5457 alloy. (a) 17 wt% H
2
SO
4
. (b) 8.8 wt% H
2
SO
4

Thermal Radiation.
Fig. 9
Effect of anodic coating thickness on reflectance of infrared radiation. Temperature of infrared radiation
source, 900 °C (1650 °F). : 99.99% Al. •: 99.50% Al. Courtesy of Aluminum Development Council
Fig. 10
Comparison of absorptance of blackbody radiation by anodized aluminum and polished aluminum.
Temperature of aluminum surface. 530 °R (21 °C, or 70 °F)
Fatigue Strength.
Anodizing Non-Aluminum Substrates
Magnesium Anodizing.
Titanium Anodizing.
Zinc Anodizing.
Thermal Spray Coatings
Robert C. Tucker, Jr., Praxair Surface Technologies, Inc.
Introduction
Fig. 1 Deformation of molten or semimolten particles resulting from spray impacting on a substrate

Fig. 2 Typical microstructure of a plasma-
sprayed tungsten metal coating showing the splat structure and the
fine crystalline structure within the splats. (a) Scanning electron micrograph of a fracture surface. (b) Light
micrograph of the same coating. Courtesy of Praxair Surface Technologies, Inc.
Acknowledgements
Metals Handbook,
Processes
Flame spray
Fig. 3 Cross sections of typical flame spray guns. (a) Wire or rod. (b) Powder
Flame spray and fuse
The electric-arc (wire-arc) spray
Fig. 4 Typical electric-arc spray device
Plasma Spray.
Fig. 5 Plasma spray process. Courtesy of Praxair Surface Technologies, Inc.

Fig. 6 Typical inert-atmosphere and/or low-pressure plasma chamber. Courtesy of Metco, Inc.

The transferred plasma-arc process
Fig. 7 Transferred plasma-arc spraying
High-Velocity Oxyfuel.
Fig. 8 High-velocity oxyfuel process. Courtesy of Praxair Surface Technologies, Inc.
Detonation Gun.
Fig. 9 Detonation gun process. Courtesy of Praxair Surface Technologies, Inc.
Process Comparison.
Ancillary Equipment.
Surface Preparation
Cleaning and Degreasing.
Surface Roughening.
Finishing Treatment
Sealing.

Coating Finishing.
μ μ R
μ μ R
Fig. 10 Recommended shapes for carbide and high-
speed steel cutting tools used in machining sprayed metal
coatings





















Coating Repair.
Quality Assurance

Metallography
μ
μ
μ
μ
μ
μ