{"id":2290,"date":"2026-02-03T11:19:41","date_gmt":"2026-02-03T03:19:41","guid":{"rendered":"https:\/\/www.hexinmusu.com\/?p=2290"},"modified":"2026-02-03T11:19:45","modified_gmt":"2026-02-03T03:19:45","slug":"lm6-aluminum-alloy-ingot","status":"publish","type":"post","link":"https:\/\/www.hexinmusu.com\/en\/lm6-aluminum-alloy-ingot.html","title":{"rendered":"LM6 Comprehensive Guide to High Silicon Cast Aluminum Alloys: Compositional Philosophy, Heat Treatment Response and High End Applications"},"content":{"rendered":"

As part of the British Standards (BS) and Commonwealth system of High Silicon Aluminum Silicon Casting Alloys<\/strong> The classic brand name of theLM6<\/strong> by means ofExcellent casting fluidity, great air tightness and excellent corrosion resistance<\/strong>and widely recognized. The alloy is typicallySub-eutectic aluminum-silicon alloys<\/strong>in order toHigh purity base with moderate magnesium content<\/strong>Characterized by significant reinforcement by heat treatment, it is a key component in the manufacture ofComplex thin-walled, high-pressure gas-tight or high-quality castings requiring high corrosion resistance.<\/strong>It is the benchmark material in the marine, chemical and high-performance engineering fields.<\/p>\n\n\n

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\"LM6<\/figure>\n<\/div>\n\n\n

Standards and grades for LM6<\/strong><\/p>\n\n\n\n

    \n
  • British\/Commonwealth Standard Grades<\/strong>: According to British Standard BS 1490, the grades are LM6<\/strong>LM\u201c stands for \u201dLight Metal\u201c. \u201dLM\" stands for \"Light Metal\".<\/li>\n\n\n\n
  • Grade Meaning<\/strong>: The classic high-silicon grades of the LM series correspond to the internationally recognized Al-Si-Mg casting alloys.<\/li>\n\n\n\n
  • Core features<\/strong>:High silicon content<\/strong>to ensure castability.Clear magnesium content<\/strong>to provide heat treatment strengthening capabilities.Strict control of impurities (iron, copper)<\/strong> for top corrosion resistance. It represents the pursuit of \u201cHigh Integrity Castings\u201d<\/strong> The technical route.<\/li>\n<\/ul>\n\n\n\n

    LM6 Aluminum Alloy Composition Table (based on BS 1490 typical requirements)<\/strong><\/p>\n\n\n\n

    elemental<\/th>Content range (wt%)<\/th>functional role<\/th><\/tr><\/thead>
    Silicon (Si)<\/strong><\/td>10.0-13.0<\/strong><\/td>core element<\/strong>It offers unmatched casting fluidity, low shrinkage and resistance to hot cracking.<\/td><\/tr>
    Magnesium (Mg)<\/strong><\/td>0.10-0.35<\/strong> or higher<\/td>Key Enhancement Elements<\/strong>. The formation of the Mg\u2082Si phase makes the alloyHigh strength can be obtained by T6 heat treatment<\/strong>. is the key to distinguishing it from simple silica-aluminum mines such as LM20.<\/td><\/tr>
    Iron (Fe)<\/strong><\/td>\u2264 0.60<\/strong><\/td>Tightly controlled impurities<\/strong>. Low iron content is a prerequisite for high elongation and excellent corrosion resistance.<\/td><\/tr>
    Copper (Cu)<\/strong><\/td>\u2264 0.10<\/strong><\/td>Tightly controlled impurities<\/strong>It is a very low copper content. The extremely low copper content ensures that in harsh environments such as seawater theTop corrosion resistance<\/strong>.<\/td><\/tr>
    Manganese (Mn)<\/strong><\/td>\u2264 0.50<\/td>Partial neutralization of iron.<\/td><\/tr>
    Zinc (Zn)<\/strong><\/td>\u2264 0.10<\/td>Strict control.<\/td><\/tr>
    Titanium (Ti)<\/strong><\/td>\u2264 0.20<\/td>Grain refiner.<\/td><\/tr>
    Aluminum (Al)<\/strong><\/td>tolerance (i.e. allowed error)<\/td>High purity matrix.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    LM6 Physical and Mechanical Properties Parameter Table (sand\/metal mold casting, typical values)<\/strong><\/p>\n\n\n\n

    Performance indicators<\/th>Cast (F)<\/th>T6 heat treatment state<\/th>Performance Positioning and Benefits<\/th><\/tr><\/thead>
    intensity<\/strong><\/td>2.66 g\/cm\u00b3<\/td>--<\/td>--<\/td><\/tr>
    Tensile strength (Rm)<\/strong><\/td>150-180 MPa<\/td>230-280 MPa<\/strong><\/td>Excellent strength after T6<\/strong>The copper-containing alloys of the Cu alloys are very similar or superior to those of many copper-containing alloys.<\/td><\/tr>
    Yield strength (Rp0.2)<\/strong><\/td>70-90 MPa<\/td>180-220 MPa<\/strong><\/td>Significantly improved by heat treatment.<\/td><\/tr>
    Elongation (A)<\/strong><\/td>6.0-10.0%<\/strong><\/td>2.0-5.0%<\/strong><\/td>Highlighting Advantages<\/strong>: Whether in the cast or T6 state, theExcellent plasticity (toughness)<\/strong>, far exceeding Al-Si-Cu alloys of the same strength level.<\/td><\/tr>
    Brinell hardness (HB)<\/strong><\/td>50-55<\/td>70-85<\/td>--<\/td><\/tr>
    fatigue strength<\/strong><\/td>favorable<\/td>talented<\/strong><\/td>Dense organization and high toughness result in excellent fatigue resistance.<\/td><\/tr>
    corrosion resistance<\/strong><\/td>excellent<\/strong><\/td>excellent<\/strong><\/td>Core Advantages<\/strong>. It is the highest grade among cast aluminum alloys and is particularly resistant to seawater corrosion.<\/td><\/tr>
    Casting mobility<\/strong><\/td>excellent<\/strong><\/td>--<\/td>Core Advantages<\/strong>The casting is suitable for the most complex castings.<\/td><\/tr>
    airtight<\/strong><\/td>excellent<\/strong><\/td>--<\/td>Good solidification characteristics, suitable for pressure castings.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    Performance Characteristics and Design Philosophy<\/strong>
    The design philosophy of the LM6 is \u201cPure, strong and corrosion-resistant.\u201d<\/strong> :<\/p>\n\n\n\n

      \n
    1. pure substrate<\/strong>: ByStrict restrictions on iron (Fe) and copper (Cu)<\/strong> and other impurities, obtained close to the theoretical optimum ofCorrosion resistance and toughness<\/strong>. This makes them more costly than general-purpose alloys, but provides for applications where reliability is critical.<\/li>\n\n\n\n
    2. Heat Treatment Flexibility<\/strong>: The well-defined magnesium (Mg) content makes its properties adjustable. It can be used either as a highly plastic cast material or through theT6 Heat Treatment<\/strong>Transformation into high-strength structural materials provides freedom of design.<\/li>\n\n\n\n
    3. Unrivaled craftsmanship<\/strong>: Extremely high silicon content ensures the highest castability of any heat-treatable aluminum alloy, enabling it to handle complex structures that are difficult to form with other high-strength alloys.<\/li>\n<\/ol>\n\n\n\n

      Corresponding international grades<\/strong>
      As a classic alloy, it has a wide range of counterparts around the world:<\/p>\n\n\n\n

        \n
      • UK\/International Standards<\/strong>:LM6<\/strong> (BS 1490) and in the ISO standard as Al-Si10Mg<\/strong>.<\/li>\n\n\n\n
      • American Standard<\/strong>:A360.0<\/strong> Close performance in die casting;356.0<\/strong> Composition is similar in sand\/metal mold casting, but the Si range is usually slightly lower (6.5-7.51 TP3T).<\/li>\n\n\n\n
      • Chinese national standard<\/strong>:ZL101A<\/strong> \u6216 ZL104<\/strong>, but LM6 has a higher Si content and castability is usually superior.<\/li>\n\n\n\n
      • EU standard<\/strong>:EN AC-43400<\/strong> \u6216 EN AC-45000<\/strong> (EN 1706).<\/li>\n\n\n\n
      • French standards<\/strong>:A-S12G<\/strong><\/li>\n\n\n\n
      • German Standard<\/strong>:G-AlSi10Mg<\/strong><\/li>\n<\/ul>\n\n\n\n

        LM6 in the foundry industry<\/strong>
        based on itsHigh integrity, corrosion resistance and toughness at the same time<\/strong>features, the LM6 is widely used where reliability is paramount:<\/p>\n\n\n\n

          \n
        1. Marine and Offshore Engineering (iconic applications)<\/strong>\n
            \n
          • Marine components<\/strong>: Outboard housings, pump\/valve housings, marine instrument mounts, deck fittings.<\/li>\n\n\n\n
          • Desalination and Chemical<\/strong>: Corrosion-resistant pump bodies, valve bodies, and line fittings.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
          • Aerospace and high-end equipment<\/strong>\n
              \n
            • Aircraft structural parts<\/strong>: Complex supports, housings, and components of maneuvering systems that are not load-bearing or sub-load-bearing.<\/li>\n\n\n\n
            • High Performance Vehicles<\/strong>: Racing suspension parts, intake manifold, oil pan (metal mold casting T6 state).<\/li>\n<\/ul>\n<\/li>\n\n\n\n
            • High-pressure and gas-tightness requirements<\/strong>\n
                \n
              • hydraulic system<\/strong>: Valve blocks, accumulator housings, high-pressure cylinders (utilizing their superior gas-tightness and weldability).<\/li>\n\n\n\n
              • Compressor components<\/strong>: Air or refrigeration compressor blocks, end caps.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
              • High quality art and architectural castings<\/strong>\n
                  \n
                • Sculptures and decorative pieces requiring high surface detail and weather resistance.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n

                  LM6 Aluminum Alloy Frequently Asked Questions<\/strong><\/p>\n\n\n\n

                  Q1: What is the difference between LM6 and LM25?<\/strong><\/p>\n\n\n\n

                    \n
                  • This is the most common comparison in the British Standard.\n
                      \n
                    • LM6<\/strong>:High Silicon (10-13%Si), Low Iron and Copper, Contains Magnesium<\/strong>.Excellent castability, corrosion resistance and toughness<\/strong>, which can be strengthened by heat treatment.<\/li>\n\n\n\n
                    • LM25<\/strong>:Medium Silicon (6.5-7.51 TP3TSi, similar to US 356.0), low Fe-Cu, Mg-containing<\/strong>.Strength (especially after T6) usually slightly higher than LM6, elongation slightly lower<\/strong>, casting fluidity is inferior to LM6.<\/li>\n\n\n\n
                    • selection<\/strong>: The QuestExtreme castability, corrosion resistance and toughness<\/strong>Select LM6; pursueMaximum strength and hardness<\/strong>LM25 can be selected when the structure permits.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n

                      Q2: Can LM6 be used for die casting?<\/strong><\/p>\n\n\n\n

                        \n
                      • Yes, but not the most typical process<\/strong>. It is more commonly found inSand casting, metal-type (gravity\/low-pressure) casting and investment casting<\/strong>Because of its magnesium content and low iron characteristics. Because of its magnesium content and low iron characteristics, used in die casting need to pay attention to anti-sticking mold problems, and its excellent performance in the slow solidification process can be more reflected. When die casting its grade may correspond to GD-AlSi10Mg<\/strong>.<\/li>\n<\/ul>\n\n\n\n

                        Q3: What is the welding and repair performance of LM6?<\/strong><\/p>\n\n\n\n

                          \n
                        • Excellent performance<\/strong>. The low impurity content gives it a low tendency to weld hot cracks. The ability to obtain strong, dense welds, both in TIG (TIG\/MIG) and filler welds, is an important advantage for its use in high-integrity castings.<\/li>\n<\/ul>\n\n\n\n

                          Q4: Why is the corrosion resistance of LM6 so outstanding?<\/strong><\/p>\n\n\n\n

                            \n
                          • The root cause is its \u201cHigh purity.\u201d<\/strong> :Very low copper (Cu) content<\/strong>Eliminates the main cathodic phase of galvanic corrosion;Low iron (Fe) content<\/strong>The possibility of forming harmful hard and brittle iron-rich phases is reduced. This enables the formation of a uniform, stable protective film of aluminum oxide on the surface.<\/li>\n<\/ul>\n\n\n\n

                            Q5: Is it possible to replace LM6 with a cheaper alloy in cost-sensitive projects?<\/strong><\/p>\n\n\n\n

                              \n
                            • Careful assessment is required<\/strong>. If the application utilizes only the LM6High castability<\/strong>And forLow corrosion resistance and toughness requirements<\/strong>In the case of a high iron or copper content, a common Al-Si alloy (e.g. LM2, LM4) may be considered as an alternative. However, if the application environmentWet, corrosive, or parts subjected to shock loads<\/strong>The substitution may lead to early failure, which may result in maintenance and replacement costs that are much higher than the material savings.LM6 is a material designed for total life cycle cost optimization.<\/strong><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

                              A classic British Standard (BS) and Commonwealth grade of high silica-aluminium-silicon casting alloy, LM6 is recognized for its excellent casting fluidity, very good hermeticity and excellent corrosion resistance. The alloy is a typical sub-eutectic aluminum-silicon alloy characterized by a high purity base with moderate magnesium content, which can be significantly strengthened by heat treatment. It is a benchmark material for the manufacture of complex, thin-walled, high-pressure gas-tight or high-quality castings with high corrosion resistance, and has a strong reputation in the marine, chemical and high-performance engineering sectors. LM6 Corresponding Standards and Grades LM6 Aluminum Alloy Composition Table (based on BS 1490 typical requirements) Element Content Range (wt%) Functional Role Silicon (Si) 10.0-13.0 Core element providing unmatched casting fluidity, low shrinkage, and resistance to hot cracking. ...<\/p>","protected":false},"author":1,"featured_media":2291,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[21],"tags":[103,121,89],"class_list":["post-2290","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-about-news","tag-die-cast-aluminum","tag-common-cast-aluminum-alloys","tag-aluminium-alloy"],"_links":{"self":[{"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/posts\/2290","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/comments?post=2290"}],"version-history":[{"count":0,"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/posts\/2290\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/media\/2291"}],"wp:attachment":[{"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/media?parent=2290"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/categories?post=2290"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hexinmusu.com\/en\/wp-json\/wp\/v2\/tags?post=2290"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}