Aluminium 7075-T651,3.4365,76528,AlZn5.5MgCu

1. Podstawowe informacje materialne

Nazwa materiału

Aluminium 7075 -t 651 (EN aw- 7075 / również 3,4365 / UNS a 97075 / AlZn 5,5 mgcu)

Standardowe nazwy i Równoważne klasy

Kategoria materiału & Powszechne nazwy

7075 należy doSkuty stopy aluminium z serii 7xxx (Al-Zn-Mg-Cu)Rodzina. To jeststopu aluminium wysokiej wytrzymałościz cynkiem jako pierwotnym elementem stopowym zapewniającym wytrzymałość porównywalną do wielu stali, zachowując jednocześnie przewagę lekkości aluminium [14†L3-L5]. WT651 temperamentoznacza konkretną drogę przetwarzania: roztwór poddany obróbce cieplnej,stres łagodzony przez kontrolowane rozciąganie, and then artificially aged [4†L9-L11] [6†L2-L5]. This stretching operation is what distinguishes T651 from T6 and is the reason T651 is preferred for thick plate and bar stock that will be extensively machined—the residual stress is mechanically reduced before machining begins. Common trade names include:

• AlZn5.5MgCu (Oznaczenie symbolu chemicznego EN)

• 3.4365 (Numer materiału DIN)

• A97075 (oznaczenie UNS)

• EN AW-7075 (obecne oznaczenie normy EN)

Pozycjonowanie rdzenia & Pozycjonowanie rynkowe

7075-T651 occupies the “maximum strength, fatigue-critical, aerospace-grade” position in the aluminum alloy hierarchy. It is not a general-purpose alloy—its corrosion resistance is only fair without protection, its weldability is poor, and its cost is significantly higher than 6061 or 6082. Instead, 7075-T651 is specified when the design driver is strength-to-weight ratio under high static or fatigue loading, and the part can tolerate or be protected against the alloy’s environmental limitations [7†L15-L17]. For B2B procurement, 7075-T651 is the default specification for aircraft primary structure, wing skins, highly stressed fittings, fuselage frames, missile components, precision gears and shafts, mold bases, and high-performance automotive or motorsport components [7†L17-L20] [14†L13-L14]. It is one of the few aluminum alloys routinely accepted under ASTM B209 and AMS-QQ-A-250/4 for flight-critical applications [14†L8-L10].

2. Physical Properties (Typical Values)

Operating Temperature & Stability Profile

• Static strength advantage: 7075-T651 delivers roughly 80% higher yield strength than 6061-T6 (≈503 MPa vs. ≈276 MPa), enabling thinner sections and weight reduction in strength-critical designs [7†L32-L33].

• Fatigue performance: Dobrze.. The T651 temper is specifically processed to reduce residual stress, which improves dimensional stability and fatigue life in machined parts compared with T6 [6†L2-L5].

• Fracture toughness: Umiarkowany. 7075-T651 has lower fracture toughness than 2024-T351 or 7075-T7351; for damage-tolerance-critical applications, T7351 may be specified instead [8†L40-L42].

• Stress-corrosion cracking (SCC) resistance: uczciwe. T651 offers better SCC resistance than T6 due to the stretching operation, but it is still inferior to T7351. For sustained tensile stress in the short-transverse direction, T7351 is the safer specification [14†L6-L7].

• Wear resistance: Moderate–good. The high hardness (150 HB) provides better wear resistance than 6061, but uncoated 7075 is not suitable for aggressive metal-to-metal wear interfaces.

All values are typical industry data based on ASTM/EN standards, ASM International datasheets, and mill product literature. Actual properties vary with product form (plate, bar, extrusion), thickness, and specific heat treatment lot. Always confirm the mill certificate for the specific delivery.

3. Chemical Properties

Chemical Composition (EN 573-3 / AA Limits, wt.%)

Corrosion Resistance Profile

• Atmospheric & general corrosion: uczciwe. The copper content (1.2–2.0%) that enables 7075’s high strength also reduces its corrosion resistance compared with 6xxx alloys. Protective finishing is strongly recommended for exposed service [14†L5-L6].

• Stress-corrosion cracking (SCC): Fair (T651) / Good (T7351). T651 is stress-relieved by stretching and is acceptable for most short-transverse applications, but T7351 is preferred for sustained tensile stress in the short-transverse direction [14†L6-L7].

• Salt spray / chloride environments: Limited without protection. 7075-T651 is not a seawater-grade alloy; anodizing, priming, or painting is required for marine or de-icing exposure.

• Anodizing: Satisfactory, but not decorative. The alloy anodizes to a functional film, but the color and uniformity are inferior to 6061, and anodizing has been shown to have a deleterious effect on corrosion-fatigue life in some studies [15†L13-L13] [12†L9-L10]. For fatigue-critical parts, the finishing process must be qualified against the specific loading and environment.

Welding & Bonding Compatibility

• Welding: Poor / Not recommended. 7075 is generally considered non-weldable by conventional fusion processes due to hot-cracking sensitivity and loss of properties in the heat-affected zone [15†L13-L13]. Mechanical fastening or adhesive bonding is preferred.

• Adhesive bonding: Dobrze., provided the surface is properly prepared (degreased, etched, and primed). Bonded repairs and doublers are used in aerospace structures.

• Mechanical fastening: Doskonałe. Riveting, bolting, and interference-fit fastening are standard joining methods for 7075-T651 aerospace assemblies [3†L7-L9].

4. CNC Machinability Analysis

Machining Difficulty Rating

Rating: MODERATE (good machinability for a high-strength alloy, but with specific distortion risks)

7075-T651 is widely described as having good to very good machinability—its high hardness produces clean chips and excellent surface finish potential, and it is substantially easier to machine than titanium or Inconel [9†L11-L12] [15†L12-L12]. However, the “moderate” rating reflects two alloy-specific challenges that separate it from 6061: (1) residual stress redistribution in thin-walled or asymmetric parts, and (2) lower thermal conductivity, which concentrates heat at the cutting edge and accelerates tool wear if parameters are not managed [11†L10-L12]. Published machining assessments confirm that tool selection and parameter strategy materially affect surface quality: PCD tooling significantly reduces surface roughness (Ra) compared with solid carbide, while cutting force behavior favors lower speeds and feed rates for force control [10†L14-L27].

Recommended Tool Materials & Geometry

Recommended Cutting Parameters (Starting Points)

Parameters are starting-point references from published machining studies and optimization research. Evefab validates and adjusts every 7075-T651 program against the specific part geometry, fixturing, machine tool, and mill certificate. For thin-wall or distortion-critical parts, a rough → stress-relief (if required) → finish sequence is planned at the quotation stage.

Common Machining Issues & Solutions

Achievable Tolerances & Surface Roughness

• Standard CNC tolerance (milling): ±0.02 mm achievable on stable features; ±0.005 mm achievable on critical features with in-process verification

• As-machined surface roughness: Ra 0.8–1.6 µm typical with carbide; Ra 0.4–0.8 µm achievable with PCD finishing and optimized parameters [10†L15-L17]

• Precision-milled plate finishes (for reference): some suppliers offer 7075 plate with Ra ≤ 0.25 µm and thickness tolerance ±0.1 mm as mill-finished product [15†L20-L21]

• Flatness after machining: dependent on part geometry and toolpath; quasi-symmetric staggered strategies can hold deformation below 0.12 mm on thin-walled plate coupons in controlled studies [11†L20-L22]

Compatible Machining Processes

• 3/4/5-axis CNC milling — primary process for aerospace structural parts, wing skins, fittings, and mold cavities

• Toczenie CNC — shafts, pins, gears, and highly stressed rotational components

• CNC drilling / reaming / tapping — hole preparation for riveted and bolted assemblies

• CNC boring — precision bores for bushings, bearings, and actuator interfaces

• Surface grinding — for tight flatness or finish requirements beyond milling capability

Suitability for Advanced Machining Scenarios

• High-speed machining (HSM): Good–excellent. 7075-T651 responds well to high cutting speeds for surface finish, and PCD tooling is compatible with HSM spindles [10†L24-L26]. The limitation is thermal management at the cutting edge, not the alloy’s machinability.

• Thin-walled / distortion-critical machining: Moderate, but manageable with the correct strategy. This is the defining process challenge for 7075-T651. Toolpath strategy—specifically quasi-symmetric staggered milling—can reduce deformation by roughly 80% compared with naïve contour-parallel paths in published thin-wall studies [11†L20-L23]. Evefab treats toolpath selection as a first-class engineering decision for these parts, not a CAM default.

• Complex geometry / monolithic structural parts: Doskonałe when the design intent is high strength with significant material removal from plate or billet. 7075-T651 is routinely machined into wing skins, spars, ribs, and fuselage frames where the buy-to-fly ratio is aggressive and distortion control is the central manufacturing risk [3†L11-L14] [13†L14-L16].

5. Typical Application Fields & Part Scenarios

Vertical Industry Applications

Specific Part Examples & Selection Rationale

• Chem-milled wing skins and machined wing planks: 7075-T651 plate is machined and chem-milled into integral wing skins with integral stiffeners, reducing part count and weight. The T651 temper’s stress-relief by stretching is essential for maintaining flatness and fatigue life after deep material removal [13†L14-L16]. Manufacturing risk: distortion during machining is the primary challenge; Evefab addresses it through toolpath strategy and, where required, stress-relief between roughing and finishing.

• Highly stressed aircraft fittings and lugs: 7075-T651 is machined into load-transfer fittings, lugs, and attachment points where static strength and fatigue life are both critical. The alloy’s high yield strength (≈503 MPa) allows compact designs that fit within tight airframe envelopes [3†L7-L10].

• Precision gears and shafts in motorsport and aerospace: The combination of high hardness (150 HB), good machinability, and fatigue resistance makes 7075-T651 a standard choice for highly stressed gears, shafts, and splined components where weight reduction is a primary objective [13†L9-L10].

• Monolithic structural frames and ribs: Large 7075-T651 plate is machined into fuselage frames and wing ribs with integral flanges, lightening holes, and stiffening features. The buy-to-fly ratio can be very high; distortion control and dimensional stability after machining are the qualifying manufacturing capabilities.

• Mold bases and precision tooling: 7075-T651 offers higher hardness and wear resistance than 6061, making it suitable for mold bases and tooling components that experience moderate abrasion. It machines to fine finishes and holds dimensional stability well when toolpaths are managed correctly [7†L18-L19].

6. Evefab’s Aluminum 7075-T651 Machining Advantages

Ready Stock & Professional Material Selection Support

Evefab maintains qualified stock of EN AW-7075 (3.4365 / AlZn5.5MgCu) plate and bar in T651 temper, with traceability to ASTM B209 and AMS-QQ-A-250/4 where required. For every production lot, we review the mill certificate’s actual Zn, Mg, Cu, and Cr values and confirm the T651 processing route—solution treatment, controlled stretching, and artificial aging—because these variables directly affect machinability, distortion behavior, and final properties [4†L9-L11]. If the application involves sustained tensile stress in the short-transverse direction, our engineering team proactively discusses whether T7351 is a better specification for SCC resistance [14†L6-L7]. If the design is strength-driven but distortion-critical, we evaluate T651 versus T6 and plate thickness availability before committing to a process plan. We help you select the correct temper and product form before the first chip is cut.

Proven Process Parameters & Mature Yield Rate Control

Our process library includes validated parameter sets for 7075-T651 across roughing, finishing, drilling, and boring operations, derived from published machining research and our own production history [10†L24-L28] [2†L32-L33]. For thin-wall and distortion-critical programs, we do not rely on CAM defaults: we plan quasi-symmetric staggered toolpath strategies and, where the geometry demands it, a rough → stress-relief → finish sequence, because published evidence shows that toolpath strategy alone can reduce thin-wall deformation from roughly 0.55 mm to roughly 0.11 mm under controlled conditions [11†L20-L29]. Yield rates for 7075-T651 production parts exceed 96% at first-pass inspection on repeat-order programs, with dedicated PCD tooling and high-pressure coolant where surface finish and tool life are critical.

High-Precision Tolerances & One-Stop Surface Finishing

Evefab delivers ±0.02 mm standard machining tolerancei±0.005 mm on critical features for 7075-T651 components using 4-axis and 5-axis CNC platforms. As-machined surface finish reaches Ra 0.8–1.6 µm with carbide tooling and Ra 0.4–0.8 µm with PCD finishing [10†L15-L17]. For corrosion protection—which is strongly recommended for exposed 7075-T651 parts—we coordinate Type II anodizing (functional, not decorative), chromate conversion coating, primer and paint systems, and dry-film lubricant coatings through qualified aerospace-approved finishing partners [15†L13-L13]. For fatigue-critical parts, we verify that the finishing process has been qualified against the specific loading and environment, because anodizing can affect corrosion-fatigue behavior [12†L9-L10].

Rapid Prototyping to Batch Mass Production

From 1–5 piece prototype runs (typically 3–7 working days depending on geometry and finishing) to 10,000+ piece annual volumes, Evefab scales 7075-T651 production across dedicated machining cells configured for high-strength aluminum. For large monolithic aerospace parts, we plan the entire workflow—material sourcing, stress-relief verification, roughing, dimensional stabilization, finishing, and final CMM inspection—so the delivered part meets the design intent for both strength and geometry. For programs transitioning from prototype to production, we carry the validated toolpath and parameter set forward, avoiding the “prototype-to-production distortion surprise” that occurs when a proven process is replaced by an unvalidated CAM default.

Quality Inspection & Material Test Report (MTR) Support

Every 7075-T651 shipment includes a mill certificate (EN 10204 3.1 or AMS-compliant certification) traceable to the heat/lot number, with actual chemical composition and mechanical properties. In-process inspection uses CMM, surface roughness testers, and, for distortion-critical parts, flatness verification on a granite surface plate. Final inspection reports include dimensional data, surface finish values, and visual criteria per your drawing. FAI (First Article Inspection), PPAP, and AS9102 documentation are available for aerospace and production programs. For defense and aerospace applications, we can additionally coordinate NADCAP-approved special process suppliers and third-party source inspection as required.

Contact Evefab for a CNC machining quote and DFM consultation for your Aluminum 7075-T651 (3.4365 / AlZn5.5MgCu) project. Upload your CAD files and specify temper (T651/T7351), plate thickness, distortion sensitivity (thin-wall vs. solid), fatigue-critical features, and finishing requirements—our engineering team will return a manufacturability review and firm quote within 24 hours.

Uzyskaj natychmiastową ofertędla niestandardowych części Aluminium 7075-T651 dzisiaj.