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The method of welding for the defects of Aluminum alloy parts

01/07/2025 admin

Which welding is the better option for the defects of Aluminum alloy parts , argon arc welding (TIG/MIG), laser welding or cold welding ?

Think about the logic for selection ,

Deformation-sensitive parts (such as machined products): cold welding → laser welding → argon arc welding
High-strength parts : laser welding → argon arc welding → cold welding
Thick and large parts/low-cost repair : TIG welding → Laser welding (high power)

These are based on a detailed comparison of the core differences, characteristics and welding deformation of argon arc welding (TIG/MIG), laser welding and cold welding . The further specific analysis is as below :

1. Basic principles and core differences,

Method	Principle	Heat input characteristics
TIG welding	The base metal and welding wire are melted by electric arc (non-melting electrode TIG/melting electrode MIG), and argon gas is used to protect the molten pool from oxidation.	High heat input and wide heat affected zone.
Laser welding	The high-energy laser beam melts the metal instantly, and the argon/helium gas is used for protection, which is a high-energy density fusion welding.	Concentrated heat input and narrow heat affected zone.
Cold welding	High-pressure plastic deformation (solid-state welding) or micro-arc discharge (micro-melting) achieves atomic-level bonding with virtually no heat generation.	Very low/no heat input , no heat affected zone.

2.The Comparison of heat affected zone width,

3. The Comparison of core features,

Characteristic	TIG/MIG welding	Laser welding	Cold welding
Heat input	High, wide heat affected zone (prone to grain coarsening)	Concentrated, narrow heat-affected zone (about 1/3 of argon arc welding)	Virtually no heat input , no heat affected zone
Welding speed	Slow (TIG) to medium (MIG)	Very fast (up to 10m/min)	Slow (spot welding/repair)
Melt Depth	Medium-deep (current dependent)	Deep and precisely controllable (high aspect ratio)	Very shallow (surface binding only)
Oxidation Control	Depends on the purity of argon gas. Aluminum alloy needs AC TIG to break the oxide film	Requires high-purity protective gas, sensitive to oxide film	No oxidation problems (normal temperature operation)
Joint strength	Close to the parent material (need high-quality welding wire and process)	≥ Parent material (deep melting welding with high density)	≤ Parent material (joining surface is the pressing area)
Applicable thickness	Thin-Thick (0.5mm~25mm+)	Thin-medium thick (0.2mm~12mm, high power up to 20mm)	Ultra-thin (≤2mm, repairing micro defects)
Equipment cost	Low (TIG) / Medium (MIG)	Very high (laser + precision motion system)	Low-Medium (Press/Micro-arc Equipment)
Technical Difficulty	Medium (TIG requires skilled workers, MIG is easy to automate)	High (needs precise parameter adjustment, centering, and protection)	Low (simple operation, mainly pressure control)
Typical Applications	Structural parts, containers, special-shaped welds	Precision parts, battery housings, aerospace parts	Precision repair (pores, scratches), electronic components, heat-sensitive parts

4. The Comparison of deformation after welding,

Method	Deformation Source	Deformation degree	Control Difficulty
TIG welding	High heat input → severe thermal expansion and contraction , large residual stress, thin parts are prone to warping and corner deformation	★★★★★ (maximum)	Thin plate deformation is difficult to control, requiring strong fixture + anti-deformation design
Laser welding	Heat input is concentrated, but aluminum alloy conducts heat quickly → local shrinkage stress is still significant (especially in long welds)	★★★☆☆ (Medium)	Parameter optimization can reduce deformation, but it is difficult to completely eliminate it
Cold welding	No thermal stress , only micro plastic deformation caused by pressure	★☆☆☆☆ (very small)	Almost no macro deformation, suitable for high-precision parts repair

5.The key points of Deformation control,

Argon arc welding : requires pre-setting of anti-deformation, segmented skip welding, and water-cooling tooling, and correction is often required after welding.
Laser welding : Pulse welding, high scanning speed, and optimized path can reduce deformation, but fixtures are still required.
Cold welding : uniform pressure is sufficient, close to “zero deformation” , and no secondary processing is required after repair.

6. Suggestions,

Pursuing zero deformation → cold welding
▶ Applicable scenarios: repair of precision instrument parts, thin-walled parts (≤2mm), heat-treated parts, electronic housings.
▶ Limitations: low strength requirements (≤80% of parent material), limited to small area repairs.
Balance strength and deformation → Laser welding
▶ Applicable scenarios: aerospace parts, sealed housings, battery welding (deep melting requirements), automated production lines.
▶ Key: High equipment investment, suitable for mass production.
Cost priority, accept controllable deformation → TIG welding
▶ Applicable scenarios: large structural parts, thick plates (>5mm), non-standard single-piece production.
▶ Skills: TIG is used for high-quality welds, MIG improves efficiency; the surface of the welding material needs to be strictly cleaned.

Conclusion,

Dimensions	TIG welding	Laser welding	Cold welding
Heat input	high	Medium-High (Concentrated)	none
Deformation	great	medium	Very small
strength	High (close to base material)	Very high (deep melting and dense)	Medium-Low
cost	Low	Very high	middle
Best Scenes	Thick plates, structural parts	Precision parts, deep melting requirements	Ultra-thin parts, zero deformation repair

The influence of material properties on welding repair selection

The different materials of aluminum alloy have significant differences in adaptability to welding repair methods due to differences in alloying elements, heat treatment characteristics, etc.,

Material Category	Feature	Optimal welding method
6xxx series ( Al-Mg-Si )	Heat treatment strengthened type, difficult to restore mechanical properties after welding	Laser welding / cold welding (low heat input)
5xxx series (Al-Mg )	Non-heat treatment strengthening, stable performance after welding	High suitability for MIG/ cold welding
2xxx series (Al-Cu )	High crack sensitivity, difficult welding	Laser welding requires preheating + post-heating
7xxx series (Al-Zn-Mg )	High strength, easy to soften	Cold welding is suitable for small area repairs, laser welding should be used with caution

Post-weld heat treatment/correction needs assessment

The impact of different welding methods on subsequent processes is as follows,

Welding method	Need heat treatment after welding?	Need Shaping calibration?	Precautions
TIG welding	T6 state is required , reheat treatment is recommended	Need (especially thin parts )	Easy to warp
Laser welding	Small thermal impact, generally no need	May need	High automation precision but high equipment cost
Cold welding	No	No	Fine repair is suitable, and structural parts are used with caution

The application of texturing on casting

24/06/2025 admin

Texture or Texturing is a technology that forms specific textures by chemically etching or laser processing the surface of metal molds. These textures will eventually be transferred to the surface of plastic or metal products, achieving both decorative and functional effects. The texture process has clear feasibility in the casting field (especially die casting) . By improving the heat resistance of the mold, deepening the texture depth, and optimizing the draft angle , it can stably produce high-value-added metal parts. The future trend is to combine 3D laser engraving with mold temperature control technology to solve the problem of texture deformation caused by high temperature.

The following are its wide application areas and technical features:

🔧1 . Main application areas

🚗Automotive industry

Interior parts : steering wheel (leather pattern), instrument panel, door panel (pear pattern or geometric pattern), etc., to enhance the touch and cover the mold line and shrinkage mark.
Functional parts : non-slip footrest, crash bar surface (increases friction).

📱Consumer Electronics

Mobile phone/computer cases (such as Galaxy S series, iPad protective cases) use laser biting to form delicate patterns (such as leather patterns and hair patterns), which are both beautiful and anti-fingerprint.
The surfaces of household appliances (audio, camera) use fine grain or matte finish to reduce reflections and hide processing defects.

🏠Building materials and bathroom

Bathroom tiles (imitation marble pattern, depth up to 3mm), door and window hardware (sandblasted pattern to resist scratching).
The surface of flower pots and tableware (stone or wood grain) enhances texture and personalization.

🖥️Industrial equipment and daily necessities

Office equipment (printers, keyboards) use satin texture, which is wear-resistant and comfortable to the touch.
Medical device handles (anti-slip texture), toy surfaces (cartoon geometric patterns).

⚙️2 . Technical characteristics and trends

🔬Traditional crafts
- Chemical etching : Use sulfuric acid, nitric acid and other solutions to corrode the mold to form leather grain, pear grain, etc. The disadvantage is that it relies on manual labor and has low environmental protection.
- Sand blasting : quickly produces uniform sand patterns, low cost but poor durability.
💡Modern technology: Laser Texturing
- Advantages :
  - No chemical pollution, precision up to 0.01mm (such as DMG five-axis laser equipment).
  - Supports complex 3D surfaces (such as automotive interior molds), and reduces working hours by 50% (a task that traditionally takes several days can be completed in 12 hours).
- Application : high-end automotive leather texture, 3C product precision texture.

The molds of the biting process can be fully applied to the casting process, especially in the field of metal die casting and gravity casting , but the process parameters need to be adjusted according to the casting characteristics. The following is a specific analysis:

✅1 . The core application of biting in casting process

1. Die casting mold (aluminum/zinc/magnesium alloy)

Surface treatment : Laser biting or chemical etching is performed on the surface of the mold cavity to form a texture (such as leather texture, fine sand texture), which is then transferred to the surface of the die-casting.
Examples :
- Automobile gearbox housing (anti-slip patterns improve operating feel).
- Laptop shell (aluminum alloy die-casting + hairline texture, replacing plastic injection molding).

2. Gravity/low pressure casting mold

Biting is used in engine block and wheel hub molds to cover metal flow marks or parting lines.

⚠️2 . Technical difficulties and solutions

Challenge	Casting process Characteristics	Countermeasures
High temperature corrosion	High molten metal temperature (aluminum: 700°C)	Use high heat-resistant mold steel (such as H13 surface nitriding treatment)
Texture wear	Strong scouring power of molten metal	Laser texturing depth ≥ 0.1mm (higher than 0.05mm for injection molding)
Demolding resistance	Large metal shrinkage rate (aluminum 6~8%)	Increase the draft angle by 50% (e.g. 5° or more for a texture depth of 0.1mm)
Surface Adhesion	Metals tend to react with molds	Chrome plating on mold surface (thickness 0.01~0.03mm)

🔧3 . Key process adjustments

Texture Design
- Avoid sharp edges and corners (to prevent turbulence of the molten metal and cause porosity).
- Anti-scour textures are preferred (such as cross grid texture > unidirectional straight texture).
Mould pretreatment
- The casting mold needs to be polished to Ra0.2μm or less before biting (to reduce the amplification of surface defects).
Laser parameter optimization
- The die-casting mold is suitable for high-energy-density fiber lasers (such as 1064nm wavelength, pulse frequency 20kHz) to ensure that the texture remains clear after thousands of castings.

🚀4 . Typical application scenarios

Automotive Parts
- Aluminum alloy door handles (anti-slip texture), center console bracket (matte fine sand texture).
Consumer Electronics
- Magnesium alloy camera body (leather texture), drone housing (geometric etching texture).
Industrial Equipment
- Hydraulic valve body (identification texture instead of marking), motor heat sink shell (pattern to increase heat dissipation area).

V. Comparison of economic benefits

Technology	Traditional casting smooth mold	Texturing mold (die casting application)
Secondary processing cost of products	Need sandblasting/electroplating	Direct molding, eliminating the need for post-processing
Mold life	300,000 times	150,000~200,000 times (recoverable after texture repair)
Added value	Basic functions	15%~30% premium (such as high-end tool handles)

In conclusion:

The texturing process has clear feasibility in the casting field (especially die casting). By improving the heat resistance of the mold, deepening the texture depth, and optimizing the draft angle , it can stably produce high-value-added metal parts. The future trend is to combine 3D laser engraving with mold temperature control technology to solve the problem of texture deformation caused by high temperature.

MIM , Machining, or Hammering?

07/08/2023 editor

Screw /Pin of hardware applied inn Kitchen or bathroom

For these kind of small stainless steel parts made of 304 with mirror effect of surface which is high end of hardware for kitchen and bathroom .Most of these kind of parts are plastic with zinc plating .The key process for this part is mirror polishing which makes the part looks more nicer surface and valuable.

How’s the price for this part? Depends on different quantities , it has different process . For example , if the quantities is less than 50,000pcs, it will be considered to be machined directly . If the quantities is over 400,000pcs, it will be considered to be hammered .

As the high cost of the mould compare to hammering, these kind part is not competitive made by MIM .

If you have some question for these kinds of parts , send email to alina@tcc-casting.com. The technician team will be happy to discuss with you .

Anodizinng VS Micro-arc oxidation on Aluminum alloy

07/04/202307/04/2023 editor

How’s the surface treatment of anodizing and Micro-arc oxidation (MAO)? We had the test .

If you have not decided yet which kind of surface treatment , Let’s talk what kind of the method is fit for your products , send email to alina@tcc-casting.com.

Iron Oxide Desulfurizer loading , Filling and Use Plan

26/07/202222/08/2022 editor

**Index Parameter:**
1. Saturated sulfur capacity: greater than or equal to 600 mg/g
2. Industrial sulfur capacity: 20%~35%
3. Penetrating sulfur capacity: more than 30%
4. Desulfurization accuracy: generally less than 0.05PPM
Uses: For the removal of H2S in various gases such as urban pipeline gas, water gas, semi-water gas, coke oven gas, steel mill raw material gas, biogas, petrochemical and other gases.

Features:

1. High desulfurization accuracy: when the imported H2S is 1000ppm, the export H2S is 0.05ppm, which is 20 times higher than the desulfurization accuracy (1ppm) of ordinary Fe2O3;

2. Fast reaction speed: the air velocity of 1000-20000h-1 is 3-6 times higher than that of ordinary Fe2O3;

3. Large working (penetration) sulfur capacity: under the conditions of 1 and 2, the one-time fine H2S sulfur capacity is 20%-25% when O2 is contained, which is 3-6 times that of ordinary Fe2O3 desulfurizers.

4. Good strength and good water resistance. Boiled in water for 2 hours or soaked for 30 days without pulverizing or mudding, and the strength remains unchanged after soaking in water and drying.

5. Wide applicable temperature range, it is better below 100℃

1. Filling

Filling with grain suction machine

2. Hoisting and filling with a crane

3. Hoisting and filling with electric hoist

The quality of the desulfurizer filling directly affects the use effect, and it must be paid enough attention. The entire desulfurizer filling process should be in charge of a special person, and the following points should be paid attention to:

1) Lay two-layer meshes smaller than 8-10 mesh stainless steel mesh on the grate board of the desulfurization tower.

(2) Lay another layer of 20-30mm, Φ20-30mm thick porcelain balls on the wire mesh.

(3) Since dust will be generated during transportation and loading and unloading, it needs to be screened before loading.

(4) Using special filling tools, the discharge pipe should be able to rotate freely, so that the material can be evenly filled around the reactor, and it is strictly forbidden to pour the desulfurizer from the middle to prevent uneven filling.

(5) The strength of the desulfurizer increases with the increase of the amount of sulfur absorbed during the use process, so it should be packed in layers in the desulfurizer. Each layer is marked according to the filling height of the desulfurizer to ensure full, level and even filling.

(6) During the filling process, it is strictly forbidden to step on the sulfur agent directly. The wooden board can be placed on the material layer, and then enter the material and check the filling situation.

(7) At the inlet of the desulfurization raw material gas, a grid plate or crushed coke block should be installed to prevent the desulfurization agent from being blown away.

2. Use

(1) The desulfurization tower generally does not need to be specially heated and consumes energy, but the outdoor desulfurization device must be kept warm in winter to prevent the gas from being overcooled, reducing the activity of the desulfurizer and the accumulation of water on the bed and worsening the operation.

(2) Try to remove tar and water before desulfurization.

(3) The desulfurizer can be replaced all at once, or it can be replaced segment by segment according to the direction of airflow.

(4) Regularly discharge the water in the water separator in front of the desulfurization tower and the bottom of the desulfurization tower, and it is strictly forbidden for the gas to enter the desulfurization tower with liquid.

(5) The operation should be stable and the use should be reasonable in order to exert its excellent performance.

3. Clean up

1. Wet cleaning

①Close the inlet and outlet pipeline valves of the desulfurization tower before cleaning, (three desulfurization towers are alternately cleaned to ensure that there are desulfurization towers that can be used normally during the operation).

② Open the manhole at the top of the tower and inject water into the desulfurization tower. The water level is based on the submerged desulfurizer, and the soaking time is more than 8 hours.

③ Drain the soaking water in the tower from the drain at the bottom of the desulfurization tower, first take out the desulfurizer in the lower layer of the desulfurization tower, and then take out the desulfurizer in the upper layer.

④ On-site must be ventilation, operators wear gas masks or long-tube ventilators. Monitor the concentration of hydrogen sulfide and combustible gas at any time on site.

⑤ Clean out the waste desulfurizer, lay it flat on the ground to dry, and then bag it (woven bag with inner film) to monitor the temperature of the desulfurizer after bagging to prevent spontaneous combustion.

⑥ Loading and shipping.

2. Dry cleaning

② Open the manhole in the lower layer of the desulfurization tower, take out the desulfurizer with tools, and monitor the site environment.

③ On-site filling, on-site forced ventilation, operators wear gas masks or long-tube ventilators, and monitor the concentration of hydrogen sulfide and combustible gas at any time.