Overview
SIST ISO 6279:2020 is an international standard established by the International Organization for Standardization (ISO) that specifies the preferred cast aluminium alloys for use in solid plain bearings. This third edition updates and replaces the previous 2006 version, ensuring the alloy compositions and mechanical property requirements meet current industry needs. The standard facilitates the selection, quality control, and testing of aluminium alloys tailored for solid plain bearings to ensure optimal performance and durability.
The document defines the chemical compositions, mechanical properties, and test methods for aluminium alloys specifically designed for solid plain bearings. While it specifies preferred alloys, it also allows for the use of alternative alloys upon agreement between manufacturers and users.
Key Topics
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Alloy Composition: SIST ISO 6279:2020 lists preferred cast aluminium alloys by chemical composition, including elements such as tin (Sn), copper (Cu), nickel (Ni), silicon (Si), iron (Fe), manganese (Mn), zinc (Zn), magnesium (Mg), and titanium (Ti). The standard details six primary alloys used in solid bearings, each with defined mass fractions.
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Mechanical Properties: The standard mandates essential mechanical properties critical for bearing functionality. These include tensile strength, elongation, Brinell hardness, proof stress, elastic modulus, thermal expansion, thermal conductivity, and density. Properties like tensile strength and elongation are subjected to quality control checks, while hardness testing might be performed on individual bearings.
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Test Methods: SIST ISO 6279:2020 requires tensile tests to be conducted as agreed by manufacturers and users, and hardness tests to follow the ISO 4384-2 standard for bearing metals. This ensures consistency and reliability in evaluating the material's suitability.
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Designation: The standard establishes a clear designation format for aluminium alloys used in bearings, allowing for simple identification. The designation includes the term "Aluminium alloy," the ISO 6279 reference, and the specific alloy name (e.g., Aluminium alloy ISO 6279 – AlSn6Cu).
Applications
SIST ISO 6279:2020 is essential for industries utilizing solid plain bearings where lightweight, high-strength, and wear-resistant materials are necessary. Typical applications include:
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Automotive Industry: Components such as suspension systems, steering parts, and engine bearings benefit from aluminium alloys specified in this standard due to their wear resistance and mechanical performance.
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Industrial Machinery: Bearings used in heavy machinery, manufacturing equipment, and conveyors gain improved durability and efficiency by adhering to ISO 6279 aluminium alloy specifications.
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Aerospace: The lightweight nature of aluminium alloys specified in ISO 6279 makes them suitable for aerospace components requiring reliable and low-friction bearing materials.
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Railway and Transportation: Solid bearings in transport vehicles, including rail cars and commercial trucks, utilize these aluminium alloys to extend service life and reduce maintenance.
Related Standards
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ISO 4384-2: This related standard provides methods for hardness testing of bearing metals, including solid materials, and complements ISO 6279’s requirements for hardness evaluations.
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ISO/IEC Directives Part 1 and Part 2: These documents describe procedures and editorial rules followed in developing ISO standards, ensuring consistency and quality.
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ISO Technical Committee ISO/123: The committee responsible for plain bearings standardization, ensuring alignment of materials, lubricants, and test methods.
By adhering to SIST ISO 6279:2020, manufacturers and users of solid plain bearings can ensure high-quality aluminium alloys that meet international specifications for composition and mechanical performance. This results in improved bearing reliability, compatibility, and service life across a wide range of engineering applications.