Influence of a powder feed rate on the properties of the plasma sprayed chromium carbide- 25% nickel chromium coating

• Main Author: Mihailo R. Mrdak
• Format: Article
• Language: English
• Published: University of Defence in Belgrade 2014-04-01
• Series: Vojnotehnički Glasnik
• Subjects: property; powders; Plasmas; feed rate; Coatings; Chromium
• Online Access: http://aseestant.ceon.rs/index.php/vtg/article/view/3793
• ISSN: 0042-8469; 2217-4753

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning /> <w:ValidateAgainstSchemas /> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables /> <w:SnapToGridInCell /> <w:ApplyBreakingRules /> <w:WrapTextWithPunct /> <w:UseAsianBreakRules /> <w:DontGrowAutofit /> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--> <p><em>The p</em><em>lasma spray process is a leading technology</em><em> of</em><em> powder depositing </em><em>in the </em><em>produc</em><em>tion of</em><em> coatings widely used in the aerospace industry for the protection of new </em><em>parts </em><em>and</em><em> for the</em><em> repair of worn </em><em>ones</em><em>.</em> <em>Cermet 75Cr₃C₂ - 25Ni(Cr) coatings based </em><em>on </em><em>Cr₃C₂ carbides are widely used to protect parts as</em><em> they</em><em> retain high values of hardness, strength and resistance to wear up to a temperature of 850°C. This paper discusses the influence of the parameters of the plasma spray deposition of 75Cr₃C₂ - 25Ni(Cr) powder on the structure and mechanical properties of the coating.</em> <em>The powder is deposited using plasma spraying at atmospheric pressure (APS).</em> <em>The plasma gas is He,</em> <em>which is an inert gas and does not react with the powder; it</em> <em>produces dense plasma with lower heat content</em> <em>and less incorporated ambient air in the plasma jet thus reducing temperature decomposition</em> <em>and decarburization of Cr₃C₂carbide.. In this study, three groups of coatings were deposited</em> <em>with</em><em> </em><em>three different </em><em>powder feed rates of:</em> <em>30, 45 and 60 g/min<strong>.</strong></em> <em>The  coating with the best properties was deposited on the inlet flange parts of the turbo - jet engine TV2-117A</em> <em>to reduce the influence of vibrations and wear. The structures and the mechanical properties of 75Cr₃C₂ - 25Ni(Cr) coatings</em> <em>are analyzed in accordance with the Pratt &amp; Whitney standard. Studies have shown that powder feed rates have an important influence on the mechanical properties and structures of 75Cr₃C₂ - 25Ni(Cr) coatings.</em></p><p class="MsoNormal" style="text-align: justify; mso-layout-grid-align: none; text-autospace: none;"> </p> <!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <mce:style><! /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} --> <!--[endif] -->