Home / News / Company News / How To Choose The Right Welding Gas And Gas Flow When Laser Welding Brass?

How To Choose The Right Welding Gas And Gas Flow When Laser Welding Brass?

Views: 148 Author: Site Editor Publish Time: 2025-06-27 Origin: Site

Inquire

Laser welding technology is an efficient and precise welding method widely used in the field of metal processing. By focusing the laser beam, laser welding can generate high temperature in a very small area, thereby achieving rapid melting and bonding of metals. This welding technology can not only effectively reduce the heat-affected zone, but also improve the strength and appearance of the welded joint. It is widely used in industries such as automobiles, aviation, electronics and medical devices.

Brass is an alloy composed of copper and zinc. It has good mechanical properties and excellent corrosion resistance, so it occupies an important position in the manufacturing industry. Due to its good thermal conductivity and welding performance, brass is widely used in parts of electrical and electronic equipment, furniture accessories, and decorations. However, brass is easily oxidized during welding, so it is particularly important to choose an appropriate shielding gas. The shielding gas can effectively prevent oxidation reactions, ensure the quality of the welded joint, and improve welding efficiency. Therefore, understanding the characteristics of brass and the selection of shielding gas during welding are essential to achieve high-quality welding.

Role of Welding Gases

Welding gas plays a vital role in the laser welding process. Its main functions include protection, improving welding quality and heat control. The following is a detailed expansion of these functions:

1. Protection

The primary function of welding gas is to protect the welding area from oxidation and contamination. The high temperature environment of laser welding easily causes the metal surface to react chemically with oxygen in the air, thereby forming oxides and reducing the strength and corrosion resistance of the welded joint. The use of appropriate shielding gas, such as argon, helium or mixed gas, can effectively isolate the air, form a protective atmosphere, avoid oxidation of the metal surface, and ensure that the original properties of the metal are maintained during welding.

2. Improve welding quality

Welding gas also has a direct impact on welding quality. High-quality shielding gas can reduce welding defects such as pores, cracks and welding unevenness. Porosity is usually caused by poor gas flow or insufficient shielding gas during welding. The appropriate gas flow and type can help discharge the gas and impurities generated during welding and reduce the probability of pore formation. At the same time, the composition and flow of the gas can also affect the shape and fluidity of the molten pool, thereby further optimizing the appearance and mechanical properties of the welded joint.

3. Thermal control

The temperature distribution during welding is critical to the welding results. The welding gas not only provides protection, but also helps regulate the temperature distribution in the welding area. By selecting the right gas and adjusting the gas flow, welding engineers can control the temperature and extension of the molten pool to achieve the desired welding results. For example, helium has good thermal conductivity and can help increase the temperature in the welding area, thereby accelerating the welding process. Argon, on the other hand, helps reduce the temperature and is suitable for heat-sensitive materials or thinner workpieces.

Choosing the right welding gas not only helps protect the welding quality, prevents oxidation and contamination, but also significantly improves welding defects and controls the heat distribution during welding to a certain extent. Therefore, when laser welding brass, understanding and correctly applying the role of welding gas is the key to achieving high-quality welding. Click here for more information

Suitable Welding Gas Selection

In the laser welding process, choosing the right welding gas is crucial to ensure the welding quality. Different gases have different characteristics and application scenarios. The following is a detailed introduction to several major welding gases:

1. Inert gas

● Argon

Argon is the most commonly used welding shielding gas. Due to its excellent inertness and non-reactivity, argon can effectively prevent oxidation of the welding area and ensure the quality of the welded joint. In addition, the low cost of argon makes it very economical in industrial applications, so it is widely used in metal materials with high welding quality requirements, including brass.

● Helium

Helium has high thermal conductivity and welding speed, which is very suitable for fast welding occasions. Due to its low density, helium can quickly cover the molten pool and improve welding efficiency. In addition, helium generates a lot of heat during welding, which can enhance the fluidity and fusion of the molten pool, which is very suitable for projects with high requirements for weld appearance. However, due to the relatively high cost of helium, it is usually used in cases where fast welding and high-temperature welding are required.

● Helium-argon mixed gas

The mixed gas of helium and argon combines the advantages of both, providing good protection and accelerating welding speed. Mixed gases are often very effective in specific applications where the heat and fluidity of welding need to be adjusted. For example, when welding materials with uneven thickness or special alloys, mixed gases can provide a more flexible welding environment.

2. Other gases

● Nitrogen

Although nitrogen is an inert gas, it is less used in brass welding. It can be used for specific welding applications, such as welding of certain alloy types. However, it should be noted that nitrogen may react with certain alloy components in brass to form nitrides, which will affect the strength and corrosion resistance of the welded joint. Therefore, when using nitrogen, the composition and possible reactions of the materials being welded must be fully evaluated.

● Carbon dioxide

Carbon dioxide is not commonly used in brass welding, but it can be considered in some special cases. Carbon dioxide has a good protective effect, but it may also cause severe oxidation reactions of the metal. Therefore, unless other gases cannot meet specific welding requirements, it is not recommended to use carbon dioxide in brass welding.

When selecting a welding gas, it is necessary to consider the characteristics of the welding material, the specific requirements of the welding, and economic factors. Argon and helium are the main choices when welding brass, and a mixture of helium and argon can provide better performance for specific conditions. Although nitrogen and carbon dioxide can be used in some cases, the possible impact on the welding results needs to be fully evaluated. Choosing the right welding gas can significantly improve the quality and reliability of the welded joint. Click here for more information

Selection of Gas Flow Rate

During the welding process, the selection of gas flow is crucial to the welding quality and efficiency. It directly affects the protection effect of the welding area and the stability of welding. The following will explore the influence of gas flow, selection principles and recommended range in depth.

1. The influence of flow on welding effect

● Too low flow: When the gas flow is too low, the protective atmosphere may not be effectively formed, resulting in the welding area being exposed to the air. This will cause the following problems:

Oxidation and welding defects: Low flow may cause the welding molten pool to contact with the air, causing oxidation of the weld metal, and then forming welding cracks, pores or other defects.

Weld joint strength reduction: Due to the presence of oxides, the mechanical strength and corrosion resistance of the weld joint will be affected, thereby reducing the reliability of the welded product.

● Too high flow: Relatively speaking, too high gas flow will also have a negative impact on welding:

Airflow turbulence: High flow may cause uneven airflow and form turbulence, which in turn makes it impossible for the shielding gas to stably cover the molten pool.

Impact on welding stability: Turbulence may destroy the thermal field distribution during welding, resulting in unstable molten pool and fluctuating welding temperature, which ultimately affects welding quality.

Increased loss: Using too high a flow rate will also increase gas consumption, leading to unnecessary economic losses.

air-cooled handheld laser welding machine sample-Suntop

2. Selection of flow range

When selecting gas flow, it is necessary to comprehensively consider the type of equipment, welding materials, welding process and on-site environment. The generally recommended flow range is usually 5-20 L/min, but this range is not fixed, and the specific flow rate should be adjusted according to actual conditions.

Equipment and welding conditions: Different welding equipment (such as TIG, MIG, inert gas welding, etc.) requires different flow rates, and it will be more secure to use the parameters recommended by the manufacturer.

Welding speed: Faster welding speeds may require an increase in gas flow to ensure that the molten pool can obtain adequate protection and will not cool quickly and oxidize due to the completion of welding.

Weld width: If the weld is wide, the flow rate may need to be increased to provide better protection, while when the weld is narrow, the flow rate can be appropriately reduced.

3. Practical operation suggestions

In actual operation, it is recommended that welding operators regularly check and adjust the gas flow rate to ensure that it is in the appropriate range:

Initial setting: Set the initial flow rate according to the equipment specifications and welding materials.

Welding process monitoring: During the welding process, pay attention to the state of the welding pool. If abnormal conditions are found (such as abnormal noise, unstable molten pool, etc.), consider adjusting the gas flow rate.

Recording and feedback: Record the welding effect under different flow rates so that the appropriate flow setting can be adjusted in future operations.

Gas flow rate plays an important role in welding. Reasonable flow rate selection can effectively improve welding quality and reduce defects. By understanding the impact of flow rate on welding effect and adjusting it according to actual working conditions, welding operators can better achieve stable and high-quality welding results. Click here for more information

Optimization of Welding Gas and Flow Rate

During the welding process, the selection of welding gas and the adjustment of flow rate play a vital role in the welding quality. To ensure the quality and reliability of the welded joint, the optimization of welding gas and flow rate needs to be achieved through systematic experiments and adjustments. The following are detailed optimization steps and methods.

1. Experimentation and adjustment

● Establish the experimental goal:

In the selection and optimization of welding gas and flow rate, the goal of the experiment must be clarified first, such as: improving welding strength, reducing welding defects or optimizing welding speed.

● Selection of gas type:

Select a suitable shielding gas according to the welding material and process type. Common shielding gases are:

Argon (Ar): Usually used for TIG welding, effectively prevents oxidation, suitable for materials such as aluminum and stainless steel.

Carbon dioxide (CO₂): Commonly used in MIG welding and suitable for welding low-alloy steel. However, its protective performance is relatively weak and it is easy to introduce oxidation.

Mixed gas: In some welding environments, the use of a mixed gas of argon and carbon dioxide can strike a balance between protection effect and cost, such as mixed gas (commonly used as 75% Ar + 25% CO₂).

● Flow adjustment:

Adjust the flow experimentally under different gas types. Generally speaking, you can start from the middle value of the recommended flow range and gradually adjust it up and down:

Gradually increase or decrease the flow: First set a baseline flow, and then increase or decrease it in small increments. For example, starting from 10 L/min, test the welding effect at different flow rates such as 9, 8, 11, and 12 L/min.

Observe the welding effect: Evaluate the effect of flow adjustment based on the appearance of the weld after welding, the weld strength, and the internal quality (such as whether there are pores, cracks, etc.).

2. Welding test

● Small-scale welding test:

When optimizing welding gas and flow, it is recommended to conduct a small-scale welding test to reduce the investment of time and cost.

Sample preparation: Prepare welding samples with the same material and welding process conditions to ensure that the test results are comparable.

Perform welding: Weld with the set gas and flow in a well-controlled and stable environment.

● Observation and recording:

After the welding test, observe the quality and related characteristics of the weld:

Appearance of the weld: Observe the uniformity of the weld and whether there are defects such as cracks and pores.

Weld strength: Perform tensile test or bending test on the weld to evaluate its mechanical properties.

Welding temperature: Consider using tools such as thermocouples to monitor temperature changes during welding.

● Fine-tune gas flow and type:

Fine-tune according to test results:

Gas flow: If there are pores or oxidation problems in the weld, consider increasing the flow; if there is turbulent air flow, reduce the flow.

Gas type: If the welding quality is not ideal when using carbon dioxide gas, try switching to argon or a mixture of argon and carbon dioxide.

Air Cooled Handheld Laser Welding Machine samples6-Suntop

Air Cooled Handheld Laser Welding Machine samples4-Suntop

Air Cooled Handheld Laser Welding Machine samples8-Suntop

Air Cooled Handheld Laser Welding Machine samples2-Suntop

3. Post-experimental evaluation and summary

● Data analysis:

Combined with the results of the welding test, conduct a comprehensive evaluation of the gas type and flow settings, and analyze their impact on welding quality and performance indicators.

● Formation of standard operating procedures:

Based on experimental data and observations, a set of standard welding gas and flow parameters are finally formed for reference when repeating welding operations in the future.

● Continuous improvement:

The process of optimizing welding gas and flow is dynamic and should be reviewed and adjusted regularly based on actual production conditions, material changes and other factors.

The optimization process of welding gas and flow is a systematic work. Through experiments and small-scale welding tests, the best parameters can be effectively found to ensure welding quality and improve production efficiency. Regular evaluation and adjustment can not only meet the requirements of different welding conditions, but also provide a solid foundation for subsequent welding operations. Click here for more information

Frequently Asked Questions and Suggestions

During the welding process, accurate control of gas quality and flow is crucial. The following is a detailed introduction to these common problems and corresponding suggestions.

1. Gas quality issues

Problem overview:

The purity of welding gas directly affects the quality of welding. If there are impurities in the gas (such as moisture, oil smoke, oxygen and other gases), it may cause defects in the weld, such as pores, oxidation, inclusions, etc., which will affect the mechanical properties and appearance of the welded joint.

Suggested measures:

● Choose a high-quality supplier: Make sure that the gas purchased comes from a reliable supply channel, choose a company that specializes in producing welding gas, and understand its gas purity standards. Common industrial gas purity requirements are 99.99% and above.

● Detect gas purity: You can ask for a gas purity test report from the gas supplier, or use professional instruments (such as gas analyzers) to regularly test the gas to ensure that its purity meets the welding requirements.

● Storage and management: Store gas bottles properly to avoid sunlight, moisture and contact with other chemicals. Check the safety status of gas bottles regularly and replace old or damaged bottles in time.

● Air filter: In the gas supply system, an air filter can be installed to remove possible moisture and particulate impurities to ensure that the gas reaching the welding machine is clean.

2. Calibration of flow meter

Problem overview:

The accuracy of the flow meter directly affects the control of gas flow. Inaccurate flow will lead to insufficient or excessive welding gas, thus affecting the welding quality. If the flow is too small, the protection effect is poor; if the flow is too large, it will not only waste gas, but also may cause weld defects.

Recommended measures:

● Regularly calibrate the flow meter: Establish a regular calibration system for the flow meter. It is recommended to calibrate it once a quarter or every six months to ensure that the flow meter is accurate. Calibration can be performed by a professional organization or by referring to the standard process provided by the manufacturer.

● Use high-precision flow meter: Select a high-precision flow meter suitable for a specific welding environment to ensure its highest calibration range and lowest flow linearity to meet the needs of different welding operations.

● Monitoring and recording: During the welding process, it is recommended to regularly record the gas flow data, analyze its changing trend, and promptly discover and eliminate the inaccuracy of the flow meter.

● Set up an alarm system: At important welding stations, you can consider setting up a flow alarm system to monitor the gas flow in real time. If it exceeds the set range, an alarm will be issued immediately to ensure timely response.

During the welding process, the management of gas quality and flow is the key to ensuring welding quality. By paying attention to gas purity and regularly calibrating the flow meter, welding defects can be effectively reduced and the quality and reliability of welded joints can be improved. Production units should formulate detailed management measures and conduct relevant inspections and maintenance on a regular basis to ensure the smooth progress of welding operations. Click here for more information

Summarize

Selecting the right welding gas and its flow rate is crucial for laser welding brass. As a metal material with good mechanical properties and strong adaptability, brass is often used in applications with high precision and high aesthetics. However, due to its easy oxidation on the surface, suitable welding gas (such as argon or helium) can not only provide the necessary protection to prevent oxidation and welding defects, but also ensure the fluidity and stability of the gas during welding. Therefore, the reasonable selection of welding gas can help improve the welding quality and extend the service life of the welded joint.

In addition, the precise control of gas flow rate should not be ignored. Insufficient flow rate may cause the welding area to be exposed to the air, thereby increasing the risk of welding defects; while excessive flow rate may cause gas waste and weld defects. Therefore, welding operators should make reasonable selections and optimizations based on the specific welding equipment, brass material characteristics and specific welding requirements to ensure that the welding process is efficient, stable and reliable in quality. By comprehensively considering these factors, the overall effect of laser welding can be greatly improved and the expected welding quality can be achieved.