{
  "title": "Metallography of powder metallurgy parts",
  "kind": "reference",
  "company": "Struers",
  "category": "Lapping, honing & superfinishing",
  "parameters": {
    "Language": "English"
  },
  "language": "en",
  "source_url": "https://www.struers.com/en/knowledge/materials/powder-metallurgy",
  "content_html": "<h2>Metallographic preparation of powder metallurgy parts</h2><p>The main challenge when preparing powder metallurgy parts for metallographic analysis is revealing the true porosity of the material after grinding and polishing. Learn how to prepare powder metallurgy parts for analysis quickly and with reproducible results.</p><p><a href=\"/files/struers-file-7c9cd5e8f247e790ef320528/powder-metallurgi.pdf\">Download the full application note</a></p><img src=\"/files/struers-file-cf0dd7fc5e033cdc1925c1db/powder-metals-signifyer-1600x500px_79f3b8ba.jpg\" alt=\"\" loading=\"lazy\"><h2>The main characteristics of powder metallurgy parts</h2><p>Powder metallurgy is a relatively common way of producing parts, particularly in the automobile industry, as it enables the high-volume production of small and intricately shaped parts with homogenous structures. In powder metallurgy, mixtures of metal (and sometimes non-metal) powders are compacted and then sintered. The manufacturing process is expensive, but the finished parts have specific advantages over wrought or cast parts. <br><br>With powder metallurgy, it is possible to:</p>\n<ul>\n<li>Alloy metals that do not normally alloy easily</li>\n<li>Produce a great variety of alloys with different properties</li>\n<li>Make fine grained homogenous structures</li>\n<li>Form complicated shapes</li>\n<li>Create parts with a superior finish</li>\n</ul>\n<p><img src=\"/files/struers-file-f2d169e5afcb1453d8c199ce/experimental-powder-metallurgy-stainless-steel-color-etched-2_01c7825b.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 1: Experimental powder metallurgy stainless steel, color etched</p>\n<p><strong>Common applications of powder metallurgy include:</strong></p>\n<ul>\n<li>Mechanical and structural parts, such as connecting rods, chain sprockets and cams</li>\n<li>Refractory metals which are difficult to produce by melting and casting</li>\n<li>Porous materials in which controlled porosity serves a specific purpose</li>\n<li>Composite materials that do not form alloys, such as copper/tungsten</li>\n<li>Special high-duty alloys, such as nickel and cobalt-based super alloys (used for jet engine parts)</li>\n<li>High-speed tool steels that have isotropic qualities and an even distribution of carbides</li>\n</ul><h2>The metallography of powder metallurgy parts</h2><p>The density of a compacted and sintered component influences its strength, ductility and hardness. Therefore, metallography of powder metallurgy parts usually includes checking for specific porosity. <br><br>In process control, metallography of powder metallurgy parts is used to check porosity, non-metallic inclusions and cross-contamination. The metallography of powder metallurgy parts also plays an important role when developing new products or improving manufacturing processes.<br><br><img src=\"/files/struers-file-e227bf10241f0dafced3f3ac/fig-13-974x732-px_61393008.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 2: Powder metallurgy steel with 0.5 % C, diffusion alloyed with Ni, Cu and Mo. Etched in picral, showing areas of fine pearlite surrounded by ferrite, martensite, bainite and Ni-rich austenite</p>\n<p><img src=\"/files/struers-file-5c2dbc820871e647348d0b4c/fig-14-974x732-px_1dce3aff.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 3: Powder metallurgy steel with 0.8 % C, pre-alloyed with 1.5 % Mo. Etched with Nital, showing dense bainite</p><h2>The production of powder metallurgy parts</h2><p>Many different metals are used to create powder metallurgy components, including iron, copper and steel powders. <br><br>Manufacturing process of iron and steel powders <img src=\"/files/struers-file-ef7d2413420663cd98efbf6b/production-diagram_071da15f.png\" alt=\"Powder metals\" width=\"500\" height=\"215\" loading=\"lazy\"><br><br><strong>Powder production</strong><br>There are two common methods of powder production: chemical and atomization.</p>\n<ul>\n<li>Chemical: The metal is converted from ore oxides directly to metal powder at a temperature below the melting point.</li>\n<li>Atomization: The molten metal alloy flows through a nozzle and is struck by high-pressure water or gas jet. Small droplets are formed which solidify into particles.</li>\n</ul>\n<p>Once produced, the metal powder is mixed. At this stage, other elements can be added, including lubricant, carbon and/or alloying elements. <br><br><strong>Compacting the powder in a carbide die</strong><br>In order to produce components, the mixed powders are compacted under high pressure in a carbide die. At this stage, the part is shaped like the finished component, but does not have the required strength. These components are known as ‘green’ parts. <br><br><strong>Sintering the component</strong><br>To develop the necessary mechanical and physical properties, the component is sintered at high temperature in a protective atmosphere. Bonding occurs through diffusion between adjacent particles. <br><br><strong>Final treatments</strong><br>Depending on the application, some parts may undergo additional treatments, including hot isostatic pressing, oil impregnation, surface hardening or plating. <br><br><img src=\"/files/struers-file-b206638371e7753d5c2a7ee2/sponge-iron-powder-sem-974x732-px_d6a6c4f4.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 4: Sponge iron powder, SEM</p><h2>Challenges when preparing powder metallurgy parts</h2><p>The main challenge when preparing powder metallurgy parts for metallographic analysis is to reveal the true porosity of the material after grinding and polishing. This can be particularly challenging with soft materials, or materials in which soft and hard materials are mixed.</p>\n<ul>\n<li>With soft metals, abraded metal can be pushed into the pores during grinding.</li>\n<li>Specimens in which hard and soft materials are mixed are prone to show pronounced relief.</li>\n<li>Green parts: Components that have been compacted but not yet sintered need particular care as they are very fragile.</li>\n</ul>\n<p><strong>Overcoming challenges when preparing powder metallurgy parts</strong></p>\n<p>The further sections on this page briefly describe how to overcome these challenges. The procedures have been used successfully in practical laboratory applications and have proven to give reproducible results. <br><br>For a more detailed description of the procedures outlined here, <a href=\"/files/struers-file-7c9cd5e8f247e790ef320528/powder-metallurgi.pdf\" rel=\"noopener noreferrer\">download the full application note</a>.</p>\n<p><img src=\"/files/struers-file-e90e9739d5d6edaed438087d/fig-2-974x732-px_675dab33.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 5: Same specimen as Fig.1 after 8 minutes of diamond polishing (3 μm)</p>\n<p><br><img src=\"/files/struers-file-c8cb9d2e120bd46f3ae9bdd6/fig-1-974x732-px_8209ebbb.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 6: Porosity of a powder metallurgy steel specimen after 4 minutes of diamond polishing (3 μm)</p><h2>Recommendations for cutting powder metallurgy parts</h2><p>Powder metallurgy parts can be made with a range of materials, including iron, copper and steel powders. The appropriate choice of cut-off wheel is dependent on the material type.</p>\n<ul>\n<li>When sectioning a single-material powder metallurgy component, select a cut-off wheel appropriate for that material.</li>\n<li>If you are sectioning a mixed-material component, choose a cut-off wheel suitable for the major material.</li>\n<li>For sintered carbides, use a resin-bonded diamond cut-off wheel.</li>\n</ul>\n<p><img src=\"/files/struers-file-a7719e6151fab5f5f7ee7680/fig-3-974x732-px_d62a8df8.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 7: Sintered tungsten carbide (WC/Co), etched with Murakami’s reagent 1500x</p>\n<p><strong>Recommendations for mounting powder metallurgy parts</strong><br>To ensure good adhesion between the mounting resin and specimen material, degrease the specimen thoroughly with acetone or toluene before mounting. <br><br>As with cutting, the best mounting method depends on the material you are working with:</p>\n<ol>\n<li>For sintered parts (mounted specimens):<br>When hot compression mounting, use either phenolic resin (<a href=\"https://www.struers.com/en/search?query=multifast&amp;page=1\" rel=\"noopener noreferrer\">MultiFast</a>) or resins containing a harder filler material (<a href=\"/records/struers-durofast-1-kg-40100044\" rel=\"noopener noreferrer\">DuroFast</a> or <a href=\"/records/struers-levofast-1-kg-40100057\" rel=\"noopener noreferrer\">LevoFast</a>).<br>When cold mounting, acrylic resins with filler (<a href=\"https://www.struers.com/en/search?query=DuroCit-3&amp;page=1\" rel=\"noopener noreferrer\">DuroCit-3</a> or <a href=\"/records/struers-levocit-powder-3-kg-40200093\" rel=\"noopener noreferrer\">LevoCit</a>) can be used.</li>\n<li>Green parts must be re-impregnated after sectioning under vacuum with a cold mounting epoxy resin (<a href=\"/records/struers-caldofix-2-resin-1-l-40200085\" rel=\"noopener noreferrer\">CaldoFix-2</a>, <a href=\"/records/struers-epofix-resin-1-l-40200030\" rel=\"noopener noreferrer\">EpoFix</a> or <a href=\"/records/struers-specifix-40-kit-1-l-resin-500-ml-curing-agent-and-required-consumables-40200049\" rel=\"noopener noreferrer\">SpeciFix-40</a>).</li>\n<li>Powders can be mounted by mixing a small amount of powder with a slow-curing epoxy resin. The mixture can be poured directly into the mounting cup.</li>\n<li>Hard metal powders can be hot compression mounted by mixing them with a fine-grained mounting resin (<a href=\"/records/struers-durofast-1-kg-40100044\" rel=\"noopener noreferrer\">DuroFast</a>). Pour the mixture into the mounting press cylinder and top it with phenolic resin.</li>\n</ol>\n<p><img src=\"/files/struers-file-d7b7eab1c0763c1c40627986/fig-4-974x732-px_f910bfac.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 8: Carbide distribution in conventionally produced steel<br><br><img src=\"/files/struers-file-fca0e0e90f429e3c4d3fe418/fig-5-974x732-px_10c88626.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 9: Carbide distribution in powder metallurgically produced steel</p>\n<p>Find out more</p>\n<p><em>Get more knowledge, expertise and insight on our <a href=\"/records/struers-metallographic-cutting-insight-struers-com-58739\" rel=\"noopener noreferrer\">cutting</a> and <a href=\"/records/struers-metallographic-mounting-insight-struers-com-61176\" rel=\"noopener noreferrer\">mounting</a> sections</em></p>\n<p><em>See our range of cutting <a href=\"/records/struers-cutting-equipment-66035\" rel=\"noopener noreferrer\">equipment</a> and <a href=\"/records/struers-consumables-for-metallographic-cutting-struers-com-60621\" rel=\"noopener noreferrer\">consumables</a></em></p>\n<p><em>See our range of mounting <a href=\"/records/struers-equipment-and-consumables-for-hot-and-cold-mounting-60639\" title=\"Mounting\" rel=\"noopener noreferrer\">equipment</a> and <a href=\"/records/struers-equipment-and-consumables-for-hot-and-cold-mounting-60639\" title=\"Mounting\" rel=\"noopener noreferrer\">consumables</a></em></p><h2>Recommendations for grinding &amp; polishing powder metallurgy parts</h2><p>As a basic principle, when grinding, fine grinding and polishing powder metals, you should use the same procedures as for ingot-based specimens of the same material. <br><br><strong>Plane grinding</strong></p>\n<ul>\n<li>Plane grinding large volumes of materials (&gt;150 HV) can be done on a diamond grinding disc (<a href=\"/records/md-surfaces-grinding-consumables-struers-com-6539e2302f4657d8\" rel=\"noopener noreferrer\">MD-Piano</a>). <a href=\"/records/struers-metallography-of-stainless-steel-insight-struers-com-59731\" rel=\"noopener noreferrer\">Stainless steel materials</a> can be plane ground on an aluminum oxide grinding surface (<a href=\"/records/md-surfaces-grinding-consumables-struers-com-6539e2302f4657d8\" rel=\"noopener noreferrer\">MD-Alto</a>).</li>\n<li>Materials &lt;150 HV can be plane ground on silicon carbide foil or paper.</li>\n</ul>\n<p><strong>Fine grinding</strong></p>\n<ul>\n<li>For fine grinding of materials &gt;150 HV use diamonds on <a href=\"/records/md-surfaces-grinding-consumables-struers-com-6539e2302f4657d8\" rel=\"noopener noreferrer\">MD-Allegro</a>.</li>\n<li>MD-Largo with diamonds is suitable for fine grinding of materials &lt;150 HV.</li>\n</ul>\n<p><strong>Diamond polishing</strong><br>During metallographic grinding, metal is pushed into the pores. If the next polishing steps are not carried out properly, residual metal ‘lids’ will be left over the pores (particularly in soft materials). If not removed, these lids will obstruct evaluation. <br><br>Therefore, fine grinding should be followed by a thorough diamond polish. It is important that the diamond polishing step is carried out long enough to reveal the true porosity of the material (see below Figs. 10-13).</p><h2>Preparation method for powder metallurgy bronze</h2><p><img src=\"/files/struers-file-94493fd43a9c113ca206e878/table-1-preparation-method-for-pm-bronze_95dc194c.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"132\" loading=\"lazy\"><br>Table 1: Preparation method for 6 specimens of P/M bronze, mounted, 30 mm dia., using the semi-automatic <a href=\"/records/tegramin-grinding-and-polishing-machine-for-high-reproducibility-struers-co-cd79bb3dc3333619\" title=\"Tegramin\" rel=\"noopener noreferrer\">Tegramin</a> 300 mm dia.</p>\n<p>As an alternative to <a href=\"https://www.struers.com/en/search?query=diapro&amp;page=1\" rel=\"noopener noreferrer\">DiaPro</a> polycrystalline diamond suspension P, 9 μm, 3 μm and 1 μm can be used together with red, green or blue lubricant.</p>\n<p><strong>Preparation method for powder metallurgy steel</strong></p>\n<p><img src=\"/files/struers-file-31afb23c7c167afafa54e0bd/table-2-preparation-method-for-pm-steel_7382864b.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"132\" loading=\"lazy\"><br>Table 2: Preparation method for 6 P/M steel specimens, mounted, 30 mm dia., using the semi-automatic Tegramin, 300 mm dia.<br><br>As an alternative to DiaPro polycrystalline diamond suspension P, 9 μm, 3 μm and 1 μm can be used together with green or blue lubricant. <br>*Alternatively, MD-Dac/DiaPro Dac 3 can also be used.</p>\n<p><strong>Preparation method for sintered carbides</strong></p>\n<p><img src=\"/files/struers-file-9dfb1dfeae00508708e8d1d2/table-3-preparation-method-for-sintered-carbides_29c4d4db.png\" alt=\"Powder Metals\" width=\"500\" height=\"121\" loading=\"lazy\"><br>Table 3: Preparation method for 6 specimens of sintered carbides, mounted, 30 mm dia., using the semi-automatic Tegramin, 300 mm dia.<br><br>As an alternative to DiaPro polycrystalline diamond suspension P, 9 μm and 3 μm can be used together with green/blue lubricant.<br>*Optional step. <br><br><img src=\"/files/struers-file-63b5a1c090af11214874cacd/fig-6-974x732-px_5d4a34bb.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 10: Surface of powder metallurgy steel after fine grinding on MD-Allegro<br><br><img src=\"/files/struers-file-48d3a9d04e946d620e04ffd4/fig-7-974x732-px_f398b142.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 11: Same sample as in Fig. 10 showing insufficient polish, showing a surface of powder metallurgy steel <br><br><img src=\"/files/struers-file-8df32688a60f6fdd5c956bde/fig-8-974x732-px_ef078e42.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 12: Same specimen as in Fig 11 after a longer polish showing correct porosity<br><br><img src=\"/files/struers-file-d86fc6edb56287e95d03ed71/fig-9-974x732-px_ca2cf59a.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 13: Larger magnification of surface from Fig. 11, showing metal ‘lids’ covering pores Cleaning and drying powder metallurgy parts After polishing, powder metallurgy specimens should be cleaned with a water/detergent mixture to remove remnants of the polishing suspension and lubricant. The specimen should then be rinsed with water, before being thoroughly rinsed with isopropanol. <br><br><img src=\"/files/struers-file-0545360d517fcafb9cba02c2/fig-10-974x732-px_0dc1795c.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 14: Water stains from cleaning can lead to misinterpretation of the structure<br><br>Find out more</p>\n<ul>\n<li>Get more knowledge, expertise and insight on our <a href=\"/records/struers-metallographic-grinding-and-polishing-insight-struers-com-58902\" rel=\"noopener noreferrer\">grinding and polishing</a> section</li>\n<li>See our range of grinding and polishing <a href=\"/records/metallographic-grinding-and-polishing-equipment-accessories-and-consumables-a78e7daf324b5593\" rel=\"noopener noreferrer\">equipment and products</a></li>\n<li>Get <a href=\"/records/consumables-for-grinding-and-polishing-struers-com-889ebda32fb7e40b\" rel=\"noopener noreferrer\">consumables</a> and <a href=\"/records/accessories-for-grinding-and-polishing-struers-com-714798bc422e3868\" rel=\"noopener noreferrer\">accessories</a> for metallographic grinding and polishing</li>\n</ul><h2>Recommendations for etching powder metallurgy parts</h2><p>When analyzing powder metallurgy specimens, it is important to know the theoretical density in order to compare it to the porosity. <br><br>We recommend examining the unetched specimen first to check the density, shape and size of the pores, oxidation and inclusions, sintering necks and free graphite (see Figs. 15 and 16). The specimen should then be etched immediately to avoid drying stains. <br><br>The recommended etching procedure for powder metallurgy specimens:</p>\n<ul>\n<li>Wet the surface with isopropanol, immerse the specimen face up into the etchant and slightly agitate.</li>\n<li>When the appropriate etching time has elapsed, take the specimen out of the etchant and rinse with isopropanol or water depending on the etchant.</li>\n<li>Dry with a stream of warm air.</li>\n</ul>\n<p><br><img src=\"/files/struers-file-0ebe74217839baeb8c813fd1/fig-11-974x732-px_d5d0574f.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 15: Powder metallurgy bronze, unetched, containing graphite (grey), and α-δ eutectoid (blue) 500x <br><br><img src=\"/files/struers-file-d6fa2c91f4eadbdb1a7ce18f/fig-12-974x732-px_98471a5c.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 16: Same as Fig.15, etched with iron-III-chloride, showing grain structure of bronze 500x <br><br><img src=\"/files/struers-file-787b5e0babe99b05fe762987/fig-17-974x732-px_17d21898.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 17: A sample that has not been etched long enough – it is difficult to distinguish the various phases</p><h2>Etching solutions</h2><p>Common chemical etching solutions for the relevant metal or alloys can be used. When working with chemicals the standard safety precautions must be observed.</p>\n<table>\n<tbody>\n<tr>\n<td>Etchants for copper powder metals and copper powder alloys</td>\n</tr>\n<tr>\n<td>100 ml water<br>20 ml hydrochloric acid<br>5 g Iron-III-chloride</td>\n<td>Etch for 10-20 seconds<br>Rinse with water followed by isopropanol</td>\n</tr>\n<tr>\n<td>100 ml water <br>10 g ammonium persulfate (use fresh only)</td>\n<td>Rinse with water followed by isopropanol</td>\n</tr>\n<tr>\n<td>Etchants for steel powder metals</td>\n</tr>\n<tr>\n<td>1-3% Nital for iron-carbon alloys, iron-carbon-copper alloys and pre-alloyed iron-molybdenum:<br>100 ml ethanol <br>1-3 ml nitric acid</td>\n<td>Etch for 10-60 seconds depending on carbon content Rinse with isopropanol</td>\n</tr>\n<tr>\n<td>Etchants for stainless steel powder metals</td>\n</tr>\n<tr>\n<td>Vilella’s reagent:<br>45 ml glycerol<br>15 ml nitric acid<br>30 ml hydrochloric acid</td>\n<td>Etch for 30 seconds to 5 minutes <br>Rinse thoroughly with water followed by isopropanol</td>\n</tr>\n<tr>\n<td>Etchants for tungsten carbide powder metals</td>\n</tr>\n<tr>\n<td>Murakami‘s reagent:<br>100 ml water<br>10 g potassium or sodium hydroxide <br>10 g potassium ferricyanide</td>\n<td>Etch by immersion or swab etch <br>Rinse thoroughly with water followed by isopropanol</td>\n</tr>\n</tbody>\n</table>\n<p><br><img src=\"/files/struers-file-feeb9074216f79189ef8e6ec/fig-16-974x732-px_5f2dac85.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 18: Etched too long <br><br><img src=\"/files/struers-file-787b5e0babe99b05fe762987/fig-17-974x732-px_17d21898.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig.19: Correct etching <br><br><a href=\"/files/struers-file-7c9cd5e8f247e790ef320528/powder-metallurgi.pdf\" rel=\"noopener noreferrer\">Download the full application note including preparation methods</a></p><h2>Summary</h2><p>Powder metallurgy is used to produce components from metals which normally would not alloy easily. Common materials include iron, copper and steel powders. <br><br>The density of a powder metallurgy component affects its strength, ductility and hardness. Therefore, metallographic control of porosity is integral to quality control. <br><br>During metallographic grinding and fine grinding, metal can be pushed into the pores, leaving residual metal ‘lids’ that obstruct evaluation. Therefore, careful grinding and polishing with diamonds is essential to ensure a true representation of the material’s structure. <br><br><img src=\"/files/struers-file-d1be73a29f4041032d9938ca/pm-steel-with-copper-infiltration-974x732-px_3a3c6449.jpg\" alt=\"Powder Metals\" width=\"500\" height=\"376\" loading=\"lazy\"><br>Fig. 20: Powder metallurgy steel with copper infiltration</p>\n<p><strong>Get insight into other materials</strong><br>Learn more about the materialography of other metals and materials. Check out our <a href=\"/records/struers-solutions-for-materials-preparation-and-materialographic-insight-struers-com-59641\" rel=\"noopener noreferrer\">materials page</a>.</p>\n<p><a></a><a href=\"/records/struers-struers-application-specialists-struers-com-59640\" rel=\"noopener noreferrer\"><img src=\"/files/struers-file-a905a915fb32928d0d6f6828/birgitte-nielsen-974x732-px_7e6f31fe.jpg\" alt=\"Holger Schnarr\" width=\"500\" height=\"376\" loading=\"lazy\"></a></p>\n<p>All images by Birgitte Nielsen, Applications specialist, Denmark<br>For specific information about the metallographic preparation of powder metallurgy parts, <a></a><a href=\"/records/struers-struers-application-specialists-struers-com-59640\" rel=\"noopener noreferrer\">contact our application specialists</a>.</p><h2>Metallography of powder metallurgy parts | Struers.com</h2><p>Get a complete guide to the metallographic preparation of powder metallurgy parts, including specific guidelines for fine grinding, diamond polishing and etching iron, copper and steel powders. Expertise and insight from Struers, the world’s leading materialographic experts.</p>",
  "summary": "Get a complete guide to the metallographic preparation of powder metallurgy parts, including specific guidelines for fine grinding, diamond polishing and etching iron, copper and steel powders. Expertise and insight from Struers, the world’s leading materialographic experts.",
  "sections": [],
  "updated_at": "2026-10-17"
}