The sandblasting process for titanium and titanium alloys is an essential surface treatment technique. Its primary purpose is to remove the oxide layer and contaminants on the surface, improve surface roughness, enhance coating adhesion, or provide specific physical and chemical properties, thereby improving the material’s mechanical properties.

Sandblasting involves using compressed air or water flow to shoot abrasives at high speed onto the surface of titanium alloys. This process helps to remove oxide layers, dirt, and impurities, improving surface roughness and adhesion. It is commonly used in surface treatment for titanium castings and forgings to ensure the effectiveness of subsequent processing or coating applications.

Benefits of Sandblasting for Titanium Alloys

Beyond cleaning and roughening the surface, sandblasting can also improve the microstructure of the material by adjusting parameters. For example, using abrasives with diameters between 0.5 to 2 mm can reduce the grain size of titanium alloys to approximately 44 nanometers, thereby enhancing fatigue resistance and stress crack resistance. Furthermore, wet abrasive blasting combined with ultrasonic vibration can reduce surface roughness while extending the life of the abrasives and improving local yield strength.

Sandblasting plays a crucial role in various fields, including medical implants and aerospace. For instance, sandblasting treatment on implant surfaces increases the surface area, promoting cell adhesion and proliferation, thereby improving osseointegration. In the integration of composite materials with titanium alloys, sandblasting significantly enhances shear strength, facilitating the bonding of the composite material to the titanium alloy.

Sandblasting Materials for Titanium and Titanium Alloys

The abrasives used in sandblasting are typically white corundum (Al2O3) or silica sand, both of which have high hardness and good cleaning effects. The sandblasting pressure is generally controlled below 0.45 MPa to avoid excessive damage to the titanium surface. The distance between the nozzle and the workpiece should be maintained between 20 mm and 400 mm, and the spray angle is controlled between 20° and 70°.

White Corundum (White Alumina)

White corundum is known for its high hardness and excellent wear resistance, making it ideal for sandblasting hard materials such as titanium and titanium alloys. Sandblasting with white corundum delivers a strong cutting force and grinding effect, particularly suitable for large surface areas. It enhances coating adhesion by roughening the surface, which improves the overall quality of the workpiece. Moreover, white corundum significantly increases surface roughness, allowing coatings to adhere better and extend the lifespan of the coating.

Silica Sand

Silica sand is often used for more gentle surface treatments in sandblasting. Its hardness and wear resistance are relatively lower compared to white corundum, making it suitable for situations where the surface requirements are not as strict. The particles of silica sand are softer, and the impact force is lower, which may not provide the intense cutting and grinding effects of white corundum.

Silicon Dioxide (SiO2)

Silicon dioxide (SiO2) is another common abrasive material used in sandblasting. Its hardness and wear resistance lie between white corundum and silica sand. SiO2 sandblasting offers a balance of effects—providing enough surface roughness to enhance coating adhesion without causing excessive damage to the workpiece, unlike white corundum. Because of its high hardness and strong grinding effect, white corundum is usually preferred in sandblasting processes for titanium and titanium alloys to achieve optimal surface treatment results.

Sandblasting is an effective surface treatment for titanium and titanium alloys, playing a pivotal role in improving surface roughness, adhesion, and mechanical properties. Whether it’s used in medical, aerospace, or composite material applications, sandblasting provides enhanced performance and durability. The choice of abrasives—ranging from white corundum to silica sand and silicon dioxide—depends on the specific needs of the material and the required surface characteristics. Understanding and optimizing the sandblasting process ensures that titanium components perform at their best in various high-demand applications.

Types of Sandblasting Processes

• 1.Dry Sandblasting Process

  Dry sandblasting is one of the most widely used and traditional methods for surface treatment. In this process, compressed air is used as the driving force to propel abrasives such as silica sand, garnet, or iron sand onto the workpiece surface at high velocity. The abrasives impact the surface, removing contaminants, scale, rust, old coatings, and other unwanted materials, while also creating a roughened texture on the surface. This rough texture is essential for improving the adhesion of coatings, paints, or other finishes.The key factors that determine the effectiveness of dry sandblasting are the choice of abrasives and the air pressure used. For example, larger steel parts thicker than 3 mm might require abrasives like silica sand with a particle size of 2.5 to 0.5 mm, combined with an air pressure range of 0.3 to 0.5 MPa. The appropriate combination of abrasives and air pressure ensures that the surface is thoroughly cleaned and prepared without causing any damage. Additionally, dry sandblasting can be adjusted to achieve different levels of roughness depending on the specific requirements of the part being treated.

  This method is commonly used for cleaning metal surfaces, preparing surfaces for coatings and paints, deburring metal parts, and texturing materials to improve adhesion. Dry sandblasting is widely adopted in automotive manufacturing, shipbuilding, steel production, and aerospace industries, where the surface preparation of large components is crucial for performance and durability.

• 2.Wet Sandblasting Process

  Wet sandblasting combines the principles of dry sandblasting with the addition of water to the abrasive material, forming a slurry mixture. This addition of water significantly reduces the amount of dust generated during the blasting process, making it ideal for use in environments that prioritize cleanliness and environmental safety. The water helps to keep the dust contained, preventing it from contaminating the air and surrounding environment, which is especially important in industries where cleanliness and air quality are paramount.The wet sandblasting process also helps to lower the surface temperature of the workpiece during treatment, as the water absorbs some of the heat generated by the friction of the abrasives against the surface. This can be crucial for preventing thermal damage to sensitive materials or components that may warp or degrade under excessive heat.

  Wet sandblasting is commonly used for surface cleaning, rust removal, and paint stripping in applications where controlling airborne dust is essential. This process is particularly valuable in industries like construction, automotive repair, and marine maintenance, where workers may need to perform surface cleaning in confined or sensitive environments.

  Furthermore, the addition of water also helps to minimize wear on both the abrasive material and the blasting equipment, extending the lifespan of these components. Wet sandblasting can also be used in industrial maintenance to prepare surfaces for coating applications, ensuring a clean and well-prepared surface for subsequent treatments.

• 3.Shot Peening Process

  Shot peening is a surface treatment method that is similar to sandblasting, but instead of using granular abrasives, it employs spherical abrasives such as steel shot, glass beads, or ceramic beads. The abrasives are propelled at high velocity onto the surface of the workpiece, but unlike traditional sandblasting, shot peening does not remove material; rather, it introduces compressive stress into the surface layers of the material.This compressive stress is highly beneficial in improving the fatigue strength and resistance to stress corrosion of metal components. By subjecting the workpiece to this process, microcracks and surface defects are closed, preventing the initiation of cracks during cyclic loading or stress. This results in enhanced durability and extended service life of critical components subjected to dynamic stresses.

  Shot peening is commonly used in the treatment of high-performance parts in industries such as aerospace, automotive, and defense, where components like gears, turbine blades, springs, and engine parts are subjected to repeated stress cycles. For example, aircraft engine components benefit greatly from shot peening, as it helps improve the resistance to fatigue and prolongs the lifespan of these high-stress parts. Similarly, automotive parts such as crankshafts and connecting rods are shot-peened to enhance their resistance to cracking and wear.

  This method is particularly suited for parts that need to withstand cyclic loading and fatigue failure, making it a critical process for precision engineering. Shot peening is also used to improve the surface hardness of materials without altering the overall material properties, making it suitable for parts that must maintain strength while resisting wear and corrosion.

• 4.Suction Sandblasting

  Suction sandblasting, also known as siphon sandblasting, utilizes a siphon tube to draw abrasive materials into the airflow. This method is particularly suitable for small, intricately shaped parts that are difficult to treat with other methods. The abrasive material, often sand, glass beads, or other grit, is sucked through the siphon and directed towards the surface by the compressed air. The low-pressure operation makes it less aggressive than pressure sandblasting, reducing the risk of damaging delicate components.This technique is widely used for light to moderate surface cleaning, de-burring, and texture creation on smaller metal parts, automotive components, and intricate castings. Because of its lower operating cost and simplicity, suction sandblasting is ideal for small workshops or businesses that require precision without high volume or extreme pressure demands. However, it may not be the best option for larger surface areas or more aggressive treatments.

• 5.Pressure Sandblasting

  Pressure sandblasting is a high-efficiency method that uses a pressurized container to accelerate abrasive materials at high speeds. This technique is especially effective for large-area surface treatment, making it the go-to choice for industrial operations where productivity is key. The high-pressure stream allows the abrasive material to hit the surface with greater force, effectively removing rust, scale, paint, and other contaminants, as well as roughening the surface for better adhesion of coatings.Pressure sandblasting is commonly used in heavy industries, such as shipbuilding, steel fabrication, and construction, where large parts, such as tanks, pipelines, and machinery, need to be cleaned or prepared for coating. The method can be tailored to suit different materials and surface profiles by adjusting the pressure and type of abrasives used. While this technique offers excellent efficiency, it also requires more sophisticated and costly equipment, making it better suited for high-volume production environments.

• 6.Wet Abrasive Blasting

  Wet abrasive blasting combines water and abrasive materials to create a slurry that is then used to clean or prepare surfaces. The addition of water helps to suppress dust, making this method particularly advantageous in environments that require strict cleanliness standards, such as pharmaceutical, food processing, and electronic industries. The water not only reduces airborne particulates but also minimizes the wear and tear on equipment by preventing the abrasive from becoming too aggressive.This process is excellent for removing coatings, rust, and dirt from delicate surfaces while preventing heat buildup and over-scratching. Wet abrasive blasting is often used for surface preparation before coating, anodizing, or other finishing processes. Additionally, the water helps to cool down the surface, which can be beneficial for sensitive materials that may be damaged by excessive heat or friction. It is also a more environmentally friendly option compared to dry sandblasting, as it reduces dust emissions and waste, and the water can often be filtered and reused in a closed-loop system.

• 7.Bead Blasting

  Bead blasting uses glass beads or other spherical abrasives to gently clean, smooth, and polish surfaces. This method is particularly effective for fine surface treatments, where the goal is to maintain the integrity and precision of the surface while removing contaminants. The spherical nature of glass beads ensures a uniform, even finish without the harshness typically associated with angular abrasives.Bead blasting is widely used in industries that require precision work, such as jewelry making, aerospace, automotive, and medical devices. For example, in the aerospace sector, bead blasting is used to treat titanium and aluminum parts to improve their appearance and resistance to corrosion. Similarly, it is a popular choice for cleaning delicate parts without altering the geometry or damaging the surface, such as precision instruments, turbine blades, and surgical implants.

  This technique can also be used for polishing metal parts to a high sheen or creating a matte finish on products like medical implants, where smoothness and biocompatibility are paramount. Glass beads provide a non-abrasive way to refine surfaces, and the process can be adjusted for varying levels of smoothness depending on the desired outcome.

• 8.Dry Ice Blasting

  Dry ice blasting is a unique cleaning method that uses dry ice pellets instead of traditional abrasives. When these pellets come into contact with the surface, they sublimate instantly, turning into gas. This rapid transition from solid to gas creates a micro-explosion that effectively removes contaminants like dirt, grease, paint, or mold without leaving any residue behind. The sublimation process leaves the surface clean and dry, with no need for additional cleanup.This method is ideal for applications where a residue-free cleaning process is required. It is often used in food processing equipment, electronics, and museum conservation, where even the smallest particles left behind could cause contamination or damage. Dry ice blasting is also an environmentally friendly option, as the dry ice is non-toxic and can be safely used without posing risks to health or the environment.

  The major advantage of dry ice blasting is that it requires no solvents or water, meaning it does not introduce any additional waste into the cleaning process. It’s perfect for cleaning sensitive equipment, machinery, or surfaces where traditional cleaning methods would be too abrasive or leave harmful residues. It’s widely used for cleaning sensitive areas in electronics manufacturing, printing presses, and historical artifact preservation, ensuring that delicate components remain in their original condition.

  Dry ice blasting uses dry ice pellets for cleaning, leaving no residue behind. It is ideal for applications requiring a residue-free cleaning process, such as food processing equipment.

Main Applications of Sandblasting

• Aerospace Industry
  Sandblasting plays a significant role in the aerospace industry, where it is used to prepare metal surfaces for coating and improve surface properties. Aircraft components, particularly those made from titanium alloys, benefit from sandblasting to enhance fatigue resistance, improve the adhesion of protective coatings, and remove oxide layers. It is also used for surface cleaning of turbine blades, engines, and other high-stress components to ensure long-term reliability.

• Automotive Industry
  In the automotive sector, sandblasting is commonly used to clean and roughen metal components such as engine parts, body panels, and exhaust systems. This process enhances the surface texture for better adhesion of coatings, paints, and primers. Additionally, sandblasting can be used to create a matte finish on alloy wheels or trim parts, providing a more attractive aesthetic.

• Medical Implants
  Sandblasting is vital in the medical field, particularly for implants like hip replacements, dental implants, and orthopedic devices. It is used to clean the surfaces of these implants, improve surface roughness, and promote osseointegration. The increased roughness facilitates better adhesion of bone tissue to the implant, improving the long-term success of the implant in the human body.

• Construction and Industrial Equipment
  Sandblasting is essential for cleaning and preparing the surfaces of large industrial machinery and structures. This includes removing old coatings, rust, or contamination from steel structures, bridges, pipelines, and tanks. It prepares the surface for repainting and extends the lifespan of the equipment. For construction machinery made from titanium alloys, sandblasting helps prevent corrosion and ensures optimal performance in harsh environments.

• Shipbuilding
  In shipbuilding, sandblasting is used for cleaning large surfaces, particularly to remove rust, old paint, and marine growth from hulls and other parts of the ship. By improving the surface quality, sandblasting allows for better adhesion of coatings designed to protect the ship from corrosion.

• Art and Decorative Finishes
  Sandblasting is also used in the creation of decorative finishes on glass, stone, and metals. Artists and designers often use sandblasting to create intricate patterns or textures on sculptures, trophies, or signage. For metals like titanium, sandblasting enhances surface texture for aesthetic purposes, especially for custom-designed jewelry or other fine titanium products.

Sandblasting in Titanium and Titanium Anodes

Titanium is a highly versatile and corrosion-resistant metal widely used in aerospace, medical implants, automotive, and industrial applications. However, its surface properties, such as adhesion ability, can be a challenge in certain processes. Sandblasting is widely used to address these challenges, providing significant benefits in the processing and treatment of titanium materials.

1. Improving Surface Adhesion for Coatings

One of the primary applications of sandblasting on titanium is to prepare its surface for the adhesion of coatings. The smooth, non-reactive surface of titanium can hinder the bonding of paints, primers, or other coatings. By using sandblasting, the surface is roughened, creating microscopic grooves that significantly improve the mechanical adhesion of coatings. This is especially critical for aerospace components, where coating adhesion is crucial to prevent corrosion or wear.

In titanium anodizing, sandblasting helps enhance the uniformity of the anodic oxide layer. The process of anodizing involves an electrochemical reaction that forms a protective oxide layer on the titanium surface, improving its corrosion resistance. When combined with sandblasting, the anodizing process becomes more effective, as the surface roughening improves the bonding of the oxide layer, leading to a more durable and aesthetically appealing finish.

2. Titanium Anodes and Surface Treatment

Titanium anodes, which are used in various electrochemical processes, benefit greatly from sandblasting. Sandblasting increases the surface roughness of titanium anodes, providing a larger surface area for reactions to occur. This roughened surface not only improves the adhesion of the anodic oxide layer but also enhances the anode’s performance in terms of electrical conductivity and corrosion resistance.

For titanium anodes, which are commonly used in industries such as electroplating, water treatment, and cathodic protection, sandblasting ensures a more uniform and consistent oxide layer. This is crucial for ensuring stable and long-lasting performance in demanding applications. The process also helps to remove impurities or oxidation from the titanium surface, ensuring a clean and effective anode.

Additionally, the enhanced surface texture of titanium anodes due to sandblasting allows for better interaction with the electrolytes in electrochemical processes, improving the efficiency and longevity of the anodes.

3. Enhancing Fatigue Resistance and Strength

Sandblasting titanium can also enhance the material’s fatigue resistance and mechanical properties. By inducing compressive stress in the surface layers, sandblasting can improve the material’s ability to withstand cyclic loading and stress, which is critical in aerospace and medical implant applications. The induced compressive stress helps prevent the initiation of cracks, which can otherwise lead to material failure. This is particularly beneficial in components exposed to dynamic loads, such as turbine blades and orthopedic implants.

 

4. Corrosion Resistance in Harsh Environments

Titanium’s resistance to corrosion is one of its greatest advantages, especially in marine, aerospace, and chemical processing environments. Sandblasting can further enhance this corrosion resistance by improving the surface properties that resist wear and degradation over time. By applying coatings and anodizing after sandblasting, titanium components are better protected against environmental stresses such as seawater, high-temperature gases, or corrosive chemicals.

 

Conclusion

Sandblasting is a highly effective surface treatment that plays a critical role in the preparation and enhancement of titanium materials. Whether it’s used to improve adhesion for coatings, increase fatigue resistance, or aid in the anodizing process, sandblasting offers a versatile and essential solution in various high-demand industries. In titanium and titanium anodes, it is especially useful for ensuring better coating adhesion, enhancing corrosion resistance, and improving mechanical properties.

The combination of sandblasting with anodizing and other surface treatments ensures that titanium components maintain optimal performance in some of the most challenging applications, from medical implants to aerospace components. Properly understanding and applying sandblasting technology in these contexts will ensure the longevity, strength, and functionality of titanium-based products in a variety of industries.

At Ehisen, we offer advanced sandblasting technology tailored to meet the specific needs of your titanium processing requirements. Whether you are looking to improve surface roughness, enhance adhesion, or ensure long-lasting performance, our cutting-edge sandblasting services provide the highest quality results. Let us help you take your titanium products to the next level with our expert surface treatment solutions.

Contact us today to learn more about how Ehisen’s advanced sandblasting processes can benefit your business and ensure the optimal performance of your titanium components!