{"id":6771,"date":"2024-11-03T12:35:07","date_gmt":"2024-11-03T12:35:07","guid":{"rendered":"https:\/\/premiumalu.com\/2024-t4-aluminum-properties\/"},"modified":"2026-08-17T14:08:01","modified_gmt":"2026-08-17T14:08:01","slug":"%d1%81%d0%b2%d0%be%d0%b9%d1%81%d1%82%d0%b2%d0%b0-%d0%b0%d0%bb%d1%8e%d0%bc%d0%b8%d0%bd%d0%b8%d1%8f-2024-t4","status":"publish","type":"post","link":"https:\/\/premiumalu.com\/ru\/%d1%81%d0%b2%d0%be%d0%b9%d1%81%d1%82%d0%b2%d0%b0-%d0%b0%d0%bb%d1%8e%d0%bc%d0%b8%d0%bd%d0%b8%d1%8f-2024-t4\/","title":{"rendered":"\u0418\u0437\u0443\u0447\u0435\u043d\u0438\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432 \u0430\u043b\u044e\u043c\u0438\u043d\u0438\u044f 2024 T4"},"content":{"rendered":"

What Is 2024 Aluminum?<\/h2>\n\n\n\n

2024 is a 2000-series aluminum alloy with copper as its primary alloying element (3.8\u20134.9% Cu, plus 1.2\u20131.8% Mg and 0.3\u20130.9% Mn). It gains strength through precipitation hardening \u2014 a controlled heat treatment cycle that forms sub-microscopic copper clusters in the aluminum lattice \u2014 rather than through cold working. The result is one of the strongest aluminum alloys available in wrought form, with a tensile strength competitive with mild steel at roughly one-third the density.<\/p>\n\n\n\n

That copper content is also why 2024 corrodes more readily than 5xxx or 6xxx alloys. In practice, the material is almost always supplied as alclad sheet (pure aluminum metallurgically bonded to the surface) or protected by anodizing or paint. It is this strength-to-weight profile that makes 2024 the default choice for airframes and high-performance machinery \u2014 and exactly why the temper you choose, especially for formed parts, matters more than the alloy itself.<\/p>\n\n\n\n

Understanding the T4 Temper<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

The full designation “T4” describes a two-step thermal treatment applied after the alloy is cast, worked to its final shape (sheet, plate, bar, or tube), and solution heat-treated.<\/p>\n\n\n\n

    \n
  1. Solution heat treatment.<\/strong>\u00a0The alloy is heated to approximately 493\u00b0C (920\u00b0F) to dissolve copper-rich precipitates into a uniform solid solution. At this temperature, the copper atoms are fully dispersed throughout the aluminum matrix. The material is then rapidly quenched \u2014 usually in cold water \u2014 to trap the copper in a supersaturated solid solution. If the alloy cooled slowly, the copper would precipitate as coarse, weakly bonded particles; the rapid quench prevents this.<\/li>\n\n\n\n
  2. Natural aging.<\/strong>\u00a0The quenched material is held at room temperature for several days. During this period, copper atoms diffuse short distances through the aluminum lattice and cluster on {100} planes, forming coherent zones known as Guinier-Preston (GP) zones. These zones strain the surrounding lattice and impede dislocation movement, which is the mechanism that increases strength. The aging process reaches near-peak strength after about 4\u20135 days and continues slowly for months, though the practical design properties stabilize within the first week.<\/li>\n<\/ol>\n\n\n\n

    The outcome is a temper that combines high tensile strength (~470 MPa UTS) with the highest ductility of the commonly specified 2024 tempers \u2014 typically 19\u201320% elongation in 50 mm. That ductility is the direct consequence of what T4 does not<\/em> include: there is no cold-work step and no stress-relief stretch. The material retains the full formability of the freshly quenched condition while still reaching full aged strength.<\/p>\n\n\n\n

    How T4 Differs from T3<\/h3>\n\n\n\n

    T3 is the closest temper to T4. Both are solution heat-treated and naturally aged. The difference is a single processing step: T3 receives a controlled cold-work reduction (typically 1\u20133%) after quenching and before natural aging. That cold work adds strain hardening \u2014 more dislocations in the lattice \u2014 which slightly increases tensile and yield strength but reduces ductility and formability.<\/p>\n\n\n\n

    For a part that will be formed, bent, or stretch-formed after heat treatment, T4 is the more practical choice. The absence of cold work means the material deforms more uniformly and tolerates tighter bend radii before cracking. For a part that will be used as-rolled or as-drawn without further forming, T3’s marginal strength advantage may be preferable. The 2024-T3 guide<\/a> covers the cold-work route in more detail.<\/p>\n\n\n\n

    2024-T4 Mechanical Properties<\/h2>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    \u041d\u0435\u0434\u0432\u0438\u0436\u0438\u043c\u043e\u0441\u0442\u044c<\/th>\u0417\u043d\u0430\u0447\u0435\u043d\u0438\u0435<\/th>\u041f\u0440\u0438\u043c\u0435\u0447\u0430\u043d\u0438\u044f<\/th><\/tr><\/thead>
    \u041f\u043b\u043e\u0442\u043d\u043e\u0441\u0442\u044c<\/td>2,78 \u0433\/\u0441\u043c\u00b3<\/td>Typical for 2xxx-series<\/td><\/tr>
    \u041f\u0440\u0435\u0434\u0435\u043b\u044c\u043d\u0430\u044f \u043f\u0440\u043e\u0447\u043d\u043e\u0441\u0442\u044c \u043d\u0430 \u0440\u0430\u0437\u0440\u044b\u0432<\/td>470 \u041c\u041f\u0430 (68 \u043a\u0441\u0438)<\/td>Longitudinal, room temperature<\/td><\/tr>
    Tensile Yield Strength (0.2% offset)<\/td>324 MPa (47 ksi)<\/td>Governs most structural design calculations<\/td><\/tr>
    \u0423\u0434\u043b\u0438\u043d\u0435\u043d\u0438\u0435 \u043f\u0440\u0438 \u0440\u0430\u0437\u0440\u044b\u0432\u0435<\/td>~19\u201320%<\/td>In 50 mm gauge; highest among 2024 tempers<\/td><\/tr>
    \u041c\u043e\u0434\u0443\u043b\u044c \u0443\u043f\u0440\u0443\u0433\u043e\u0441\u0442\u0438<\/td>73.1 GPa (10,600 ksi)<\/td>Approximately one-third of steel<\/td><\/tr>
    Fatigue Strength (5\u00d710\u2078 cycles)<\/td>~140 MPa (20 ksi)<\/td>Smooth specimen, R = \u22121<\/td><\/tr>
    \u041f\u0440\u043e\u0447\u043d\u043e\u0441\u0442\u044c \u043d\u0430 \u0441\u0434\u0432\u0438\u0433<\/td>285 MPa (41 ksi)<\/td>Relevant for fastener and rivet joint design<\/td><\/tr>
    \u0422\u0432\u0435\u0440\u0434\u043e\u0441\u0442\u044c \u043f\u043e \u0411\u0440\u0438\u043d\u0435\u043b\u043b\u044e<\/td>120 HB<\/td>500 kg load, 10 mm ball<\/td><\/tr>
    \u042d\u043b\u0435\u043a\u0442\u0440\u043e\u043f\u0440\u043e\u0432\u043e\u0434\u043d\u043e\u0441\u0442\u044c<\/td>30% IACS<\/td>Low for aluminum \u2014 specify for strength, not current carrying<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    The yield strength of 324 MPa is the number that governs most structural designs. What distinguishes T4 from the other 2024 tempers is not the yield value \u2014 T351 reaches the same 325 MPa \u2014 but the elongation. At ~20%, T4 retains roughly 30\u201340% more ductility than T351 (~12\u201315%) and nearly double the ductility of T6 (~8\u201310%). That difference shows up directly in formability: a T4 sheet can be bent to a tighter radius or stretch-formed further before cracking than the same alloy in T3, T351, or T6.<\/p>\n\n\n\n

    Where 2024-T4 Is Used<\/h2>\n\n\n\n
    \"\"<\/figure>\n\n\n\n

    The combination of high strength, fatigue resistance, and superior ductility makes T4 the standard temper for formed aerospace sheet and for applications where the material must be shaped after heat treatment.<\/p>\n\n\n\n

    \u0410\u044d\u0440\u043e\u043a\u043e\u0441\u043c\u0438\u0447\u0435\u0441\u043a\u0438\u0435 \u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0446\u0438\u0438<\/h3>\n\n\n\n

    The primary application domain. Wing skins, fuselage panels, and structural covers are often formed from 2024-T4 sheet in the alclad condition. The forming operations \u2014 brake bending, stretch forming, or roll forming \u2014 take advantage of T4’s high elongation to achieve complex contours without cracking. Once formed, the part retains the full aged strength of the temper.<\/p>\n\n\n\n

    Wing lower skins and fuselage skins experience tension-dominated fatigue cycles during each flight. 2024-T4 provides the fatigue endurance needed for long service lives while keeping weight at approximately one-third of an equivalent steel design. The alclad layer protects against the corrosion that would otherwise limit the bare alloy’s service life in humid or salt-laden environments.<\/p>\n\n\n\n

    For machined structural components \u2014 bulkheads, fittings, brackets \u2014 T351 is typically preferred over T4 because the stress-relief stretch prevents machining distortion. T4’s role is specifically in formed sheet and light plate where forming capability matters more than machining stability. For a broader alloy-to-alloy comparison, the 2024 vs 7075 analysis<\/a> covers when each alloy family fits.<\/p>\n\n\n\n

    Other High-Stress Applications<\/h3>\n\n\n\n