The Quality Requirements For Aviation Parts Are Getting Higher Higher, The Difficulties In Processing Typical Aviation Parts Are Explored In Depth

With The Rapid Development Of The Aerospace Industry, The Requirements For Material Performance Are Getting Higher Higher. Difficult-To-Process Materials Such As Titanium Alloys, High-Temperature Alloys Composite Materials Are Becoming More More Widely Used. For Example, Titanium Alloys Are Mainly Used In Engine Brackets, Thrust Joints, Landing Gears, Impellers Other Parts; High-Temperature Alloys Are Mainly Used In Shafts, Disc Shafts, Turbine Discs, Combustion Chamber Casings, Integral Blades, Etc.; Composite Materials Are Mainly Used In Central Wing Boxes, Vertical Tails Wings. The Complex Structural Characteristics Of Aerospace Parts, The Difficult-To-Process Material Characteristics, The High Processing Costs Have Long Plagued The Field Of Aerospace Machining . Huiwen Intelligent Manufacturing Company Focuses On The Processing Of High-Precision, High-Difficulty, Easy-To-Deform Metal Plastic Parts , The Small Medium-Scale Production Manufacturing Of Lightweight Alloy Composite Materials (Such As Magnesium Alloys , Magnesium-Aluminum Alloys , Carbon Fiber, Etc.). By Using Machining Processes To Increase The Effective Load Of Products Significantly Reduce Their Comprehensive Costs, It Has A Wide Range Of Uses In Aerospace, Weapons Military Industry, Petrochemicals, Mechanical Instruments, 3C Electronics, Internet Of Things, Medical Other Fields.

With The Development Of Aerospace Technology, The Quality Requirements Of Aviation Parts Are Getting Higher Higher. Aluminum Alloys Are Widely Used In Aerospace Parts Due To Their Light Weight Good Performance . Due To The Special Properties Of Aluminum Alloy Materials, The Processing Requirements Are Relatively High. This Article Will Briefly Introduce The Aviation Aluminum Alloy Forming Process By Combining The Product Characteristics Of Huiwen Company.

Material Flow

Material Flow Requirements Are Usually Marked On The Drawings. Figure 1 Shows The Material Flow Marking Method Of Airbus. Aircraft Parts Often Have Specified Material Flow Directions. The Material Flow Direction Of Aluminum Alloy Sheets Is Usually In The Length Direction Of The Sheet. This Is The First Thing To Be Determined Before Forming, Because It Is Related To The Layout Direction Of Sheet Metal Cutting. Otherwise, The Appearance Size Of The Parts Will Be Correct. However, If The Material Flow Does Meet The Requirements, It Will Have A Serious Impact On The Strength Of The Parts.

Figure 1 Schematic Diagram Of Material Flow

Cutting

For Blanking Of Aviation Aluminum Alloy Sheets, Traditional Machining Methods Are Usually Preferred. As Shown In Figure 2, CNC Blanking Of Batch Typesetting CNC Milling Machines Is Used. Secondly, Die Punching Can Be Selected, But It Should Be Noted That Different Customers Have Different Specific Requirements For Whether The Holes On The Parts Can Be Punched. For Example, The Holes On Airbus Parts Cannot Be Punched, But Some Of Boeing's Parts Can Be Punched. Other Blanking Methods, Such As Laser Cutting, Wire Cutting Other Process Methods Cannot Be Used At Will. It Is Necessary To Submit The Corresponding Data Card Parameters Samples To The Customer For Approval Obtain The Approval Qualification Of The Relevant Audit Agency Before The Process Method Can Be Used Within The Validity Period.

Figure 2 Batch Typesetting CNC Milling Machine CNC Cutting

Heat Treatment Low Temperature Storage

Annealing Solution

The Forming Of Aviation Aluminum Alloy Materials Is Limited By Shape, Usually The Forming Of Complex Parts Requires Heat Treatment. Taking Our Company As An Example, We Use 2 Series Plates More Often. When The Material State Is T4 T6, It Cannot Be Formed Directly. It Needs To Be Annealed Solid Solution In Advance Before Forming. Otherwise, The Forming R Angle Will Crack. It Depends On The Size Of The Forming R Angle. The Smaller The R, The More Likely It Is To Crack.

Annealed Aluminum Alloy Materials Are Very Easy To Form, But They Also Have Disadvantages. After The Annealed Material Is Formed, It Needs To Be Treated With Solid Solution Aging Treatment To Adjust The Material State To Meet The Strength Requirements. Because The Parts Are Prone To Deformation Again During The Solid Solution Process, A Correction Finishing Process Must Be Added After The Solid Solution. Solid Solution Heat Treatment Is Also A Way To Adjust The Hardness Of The Material To Facilitate Forming. Compared With Annealing, The Forming Performance Is Slightly Worse. The Advantage Is That After Forming, Only Aging Treatment Is Required To Meet The Material Strength Requirements. However, The Disadvantage Is That The Solid Solution Material Needs To Be Stored At Low Temperature Before Forming, There Is A Time Limit During The Forming Process Low Temperature Storage. Otherwise, The Material State Will Slowly Change Harden In The Air, Which Is Conducive To Forming.

Leveling

Annealed Solution-Treated Materials Will Have Large Deformations Need To Be Leveled Using Leveling Equipment (Figure 3). The Leveled Material Should Be Unfolded Confirmed Again Before Forming To Prevent Deformation Distortion After Leveling That May Affect The Forming Size.

Figure 3 Leveling Equipment

Low Temperature Storage

Annealed Annealed (O State) Materials Can Be Stored In Natural Environment At Room Temperature, While Materials After Solution Heat Treatment (W State) Must Be Stored At Low Temperature To Maintain The Material State. Usually, They Are Immediately Transferred To A Refrigerator At About Minus 20 Degrees After Heat Treatment. When Leveling Forming Are Required, They Are Taken Out Of The Refrigerator All Forming Processes Are Completed Within The Time Specified By The Customer. It Should Be Noted That Different Customers Have Different Requirements For Refrigerator Storage Time Processing Time. For Example, Airbus Stipulates That The Refrigerator Storage Time Shall Exceed 150 Hours.

Forming - Manual Forming

Commonly Used Tools Are Shown In Figure 4, Which Left To Right Are Ruler, Wooden Hammer, Rubber Hammer, Aluminum Sheet Metal Hammer.

Figure 4 Tools Used For Manual Forming

Bending

The Main Ones Are Bending Machines (Figure 5) Bending Dies. Due To The Characteristics Of Aviation Parts, The Bending Angles R Angles Of Parts Are More Numerous.

Figure 5 Bending Machine

Rubber Forming

I Believe That Many People Are Familiar With The Concept Of Rubber Bladder Forming. Rubber Forming Is A Kind Of Evolution Rubber Bladder Forming. It Can Be Understood As A Simplified Rubber Bladder. It Also Belongs To The Category Of Mold Forming. It Uses A Hydraulic Press To Apply Pressure To The Rubber To Wrap The Material Onto The Punch To Form. Figure 7 Shows The Mold The Corresponding Aviation Sheet Metal Parts, Figure 8 Shows A 1500t Rubber Forming Press. This Flexible Sheet Metal Forming Method Is Also Widely Used In The Aviation Sheet Metal Manufacturing Industry, Especially The Stretching Forming Of Some Complex Curved Surfaces.

Aging Treatment

Aging Treatment Is For Annealed Solution Treated Parts, Is Divided Into Natural Aging Artificial Aging. It Is Mainly Selected According To The Customer's Requirements For The Final State Of The Part Material. After The Part Material Has Been Aged, No Further Forming Processing Can Be Performed. If Necessary, Re-Annealing Solution Treatment Is Required.

Mold Anti-Deformation Compensation

When Processing Rubber Forming Dies, Attention Should Be Paid To The Setting Of Positioning Holes Anti-Deformation Compensation. If It Is A Curved Surface Forming, It Is Generally Necessary To Test It Several Times In Advance To Determine The Amount Of Curvature Compensation. The Compensation Of The Flanging Angle Needs To Be Based On The Material State. When The Annealed Material Is Formed, Because The Annealed Material Has Good Forming Performance, The Compensation Amount Can Be Relatively Small. Taking 90° Flanging Forming As An Example, The Mold Forming Angle Compensation Is Usually 3°; When Using Solid Solution Material For Forming, The Mold Forming Angle Compensation Is Usually 5°. For Some Parts With More Complex Forming Areas, You Can Consider Using A Cover Plate. Figure 9 Shows The Product Mold Angle Compensation.

Shape

Shape Correction Is An Indispensable Process For Complex Formed Parts Of Aviation Aluminum Alloys. Due To Various Factors, The Parts After Forming Cannot Fit The Mold Completely. In Some Places, Due To Material Expansion Contraction, It Is Necessary To Locally Extend Shrink The Material. Usually, Cold Forming Material Collection Discharge Equipment, Commonly Known As Yago Machine (Figure 10) Is Used For Shape Correction.

NDT

If The Customer Process Requires Surface Crack Detection, Fluorescent Powder Is Usually Used For Penetration Then Observed Under Ultraviolet Light.

Conclusion

The Manufacturing Of Aviation Parts Requires Process Control, Data Recording, Attention To Detail. The Above Process Is Mainly For The Forming Of General Aviation Aluminum Alloy Parts. In Addition To Paying Attention To The Above Aspects, The Forming Of Some Complex Parts Also Needs To Be Formed In Multiple Times. This Article Will Elaborate On It, We Will Have The Opportunity To Discuss Share It Later.