Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Protective coatings for Al press tools used in automotive industry
University West, Department of Engineering Science, Division of Manufacturing Processes.
2014 (English)Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesisAlternative title
Protective coatings for Al press tools used in automotive industry (Swedish)
Abstract [en]

The application of the thermally sprayed WC-Co and Cr 3C2-NiCr coatings have been widely used in industry for its superior sliding, abrasive and erosive wear properties. The Al2O3 coating possessing high hardness can be utilized to improve the wear resistance of the metallic surface. Replacing the stamping tool material from steel to lightweight aluminium with protective coatings offers significant gains such as reduction in power costs and increasing operational efficiency during manufacturing of sheet automobile parts. In this study, the WC-CoCr and Cr3C2-NiCr coatings were sprayed with High Velocity Air-Fuel (HVAF) process and Al2O3 coating was deposited using Atmosphere Plasma Spraying (APS) process. The coatings were evaluated and compared based on the results of roughness tests, hardness tests, adhesion tests, quantitative imaging analysis and microstructure analysis. The experimental results revealed that the roughness value varied in a lower range which implies of a high density of the coatings. It was found that coatings have an extremely high hardness value as tested by the Vickers hardness test. The WC-Co coating was found to be the hardest (1215.2HV). The adhesion test was implemented according to the ASTM C633-79 standard. The result showed that WC-Co and Cr3C2-NiCr coatings without a bond coat had high tensile strength, higher than the respective glue strength (63.54MPa, 75.89MPa). Whereas, the Al2O3 coating has a much lower tensile strength (15.2MPa, 25.68MPa, with and without bond) than others and using a bond coat layer does not contribute to an increase in adhesion strength of the cermet coatings. The coating thickness was evaluated using Light Optical Microscopy (LOM) and microstructure analysis was carried out using Scanning Electron Microscopy (SEM). From the microstructure analysis, it was observed that all the coatings have a dense microstructure, very low porosity and low oxide inclusions in top coat. The WC and Cr3C2 grains retain a large volume fraction of finely dispersed in matrix. The alumina coating was found to have low levels of un-melted or the re-solidified particles in the coating. All of the aforementioned analysis and results reveal that WC/CoCr and Cr3C2-NiCr coating show promising potential for press tool applications. However, abrasive resistance test still remained to be done and will be performed in the future. The result of it can reveal the actual wear resistance between two coatings in reality and will be helpful in determining the better protective coating for aluminium press tools

Place, publisher, year, edition, pages
2014.
Keywords [en]
Protective coating, HVAF, APS, Aluminium substrate, Wear resistance
National Category
Mechanical Engineering
Identifiers
URN: urn:nbn:se:hv:diva-6858Local ID: EXP800OAI: oai:DiVA.org:hv-6858DiVA, id: diva2:756150
Subject / course
Mechanical engineering
Educational program
Produktionsteknik
Supervisors
Examiners
Available from: 2014-10-20 Created: 2014-10-16 Last updated: 2016-11-21Bibliographically approved

Open Access in DiVA

fulltext(2371 kB)633 downloads
File information
File name FULLTEXT01.pdfFile size 2371 kBChecksum SHA-512
a0816b5238cc9e1a2f4836a6f89a96553f941044220fb3f28641b4a28621b9ee9afc3f37d1407eb34f9bde29589db5be781d937ac68d49548028c9115d79c85e
Type fulltextMimetype application/pdf

By organisation
Division of Manufacturing Processes
Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 640 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 395 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf