Charles G's Posts

Chromium plating is a widely used technique for coating metal surfaces with a layer of chromium. It provides several benefits, such as corrosion resistance, improved hardness and wear resistance, and aesthetic appeal. However, chromium plating can also pose significant environmental challenges because of the toxic nature of chromium compounds. To win the environmental challenges of chromium plating, here are some strategies you can follow:

Use alternative plating methods 

One way to reduce the environmental impact of chromium plating is to explore alternative plating methods that do not use chromium compounds. For example, electroless nickel plating or electroplating with non-chromium-based solutions can provide similar benefits without the toxic effects of chromium.

Optimize process parameters

Another way to reduce the environmental impact of chromium plating is to optimize the process parameters. This can include using lower concentrations of chromium compounds, reducing plating time, or adjusting the temperature and pH of the plating solution.

Implement a closed-loop system 

Implementing a closed-loop system can reduce the amount of chromium discharged into the environment. A closed-loop system recirculates the plating solution, rather than disposing of it after each use, reducing the amount of waste generated.

Use a chemical recovery system

A chemical recovery system can help to recover the chromium from the plating solution and recycle it for future use. This reduces the amount of chromium needed for the plating process and minimizes the amount of waste generated.

Proper waste management 

Proper waste management is essential to minimize the environmental impact of chromium plating. All waste generated during the plating process should be collected, treated, and disposed of appropriately, following local environmental regulations.

In conclusion, winning the environmental challenges of chromium plating requires a combination of strategies, such as using alternative plating methods, optimizing process parameters, implementing closed-loop and chemical recovery systems, and proper waste management. By following these strategies, we can ensure that chromium plating is a sustainable and environmentally friendly process.

Hexavalent chromium, also known as chromium (VI), is a toxic and carcinogenic substance that has been widely used in the metal finishing industry for hard and decorative plating processes since the 1920s. The exceptional physical characteristics of chromium plating make it a preferred choice in many applications, but the hazardous nature of hexavalent chromium has led to increased environmental and health concerns.

The US Environmental Protection Agency (EPA) has classified hexavalent chromium as a hazardous substance and has established regulations to limit its discharge into the environment. The Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) program in the European Union has also listed chromium trioxide, a common source of hexavalent chromium in plating solutions, as a hazardous chemical and has implemented strict regulations on its use.

Because of these regulations, the metal finishing industry has been working to develop alternative plating methods and to improve the sustainability of chromium plating processes. This includes the use of closed-loop systems, chemical recovery systems, and the development of non-chromium-based plating solutions.

It is important to continue to monitor and regulate the use of hexavalent chromium to minimize its impact on the environment and public health.

Chromium plating has been widely used in various industries for decades due to its exceptional physical characteristics such as corrosion and wear resistance, and aesthetic appeal. In the aerospace industry, hard chromium is commonly used for its durability and ability to withstand extreme environments. The automotive sector primarily uses decorative chromium plating, while other industries use both decorative and hard chromium plating.

Chromium is the only element among groups 4, 5, and 6 of the periodic table that can be plated using an aqueous solution. Ionic liquids can deposit most of the transition elements, but they are not widely used in industrial applications. Aqueous hexavalent chromium deposits have exceptional tribological and corrosion resistance properties, although not all formulations possess these properties.

Chromium plating is commonly used on high-strength steels and nickel alloys, and a Wood's nickel strike is often used to prepare the surface for plating. The chromium deposit exists in the alpha phase and is crystalline, with limited compounds or components and occlusion of hydrogen and carbon, which can lead to the development of internal deposit stress.

The low cathode current efficiency of the electrolyte used for chromium plating allows for greater tribological properties because of the presence of hydride and carbide compounds. However, these compounds can also develop intrinsic stress in the deposit and affect its deformation properties.

Despite its extensive applications and good properties, chromium plating poses significant environmental challenges due to the toxic nature of hexavalent chromium. As mentioned earlier, the US EPA and REACH have established regulations to limit its discharge into the environment, and the metal finishing industry has been working to develop more sustainable plating processes. It is essential to continue to monitor and regulate the use of chromium plating to minimize its impact on the environment and public health.

The original hexavalent chromium plating formula was developed by accident in the early 1900s and it comprised of chromium trioxide and sulfuric acid. The researcher who developed the formula initially assumed that chromium trioxide was a trivalent salt, but this was later corrected by another scientist.

Since then, alternative methods of hexavalent chromium plating have been developed to address environmental and health concerns. Trivalent chromium plating, cobalt alloy deposits, and electroless nickel deposits with phosphorus or boron alloys are some of the substitute methods that have been developed and continue to be researched.

In recent years, there has also been increased interest in high-temperature and room-temperature ionic liquids for depositing metals such as trivalent chromium, niobium, aluminum, and molybdenum. These alternative methods offer the potential for more sustainable and environmentally friendly plating processes. However, more research is needed to develop and optimize these methods for industrial use.

Yes, trivalent chromium plating is an alternative to hexavalent chromium plating and can produce similar decorative deposits. However, there can be variations in deposit characteristics, particularly on hard chromium applications where macrocracks can develop after baking.

Comparing the microstructure on transverse sections can be a useful practice in analyzing macrocracks.

Electroless nickel deposits with boron alloys can offer some tribological properties, but they may not offer comparable wear and corrosion resistance properties of hard hexavalent chromium plating. Similarly, while ionic liquid methods, particularly room temperature ionic liquid electrolysis, offer potential advantages, they are still emerging technologies and require further development.

Vapor deposition methods, including chemical vapor deposition (CVD), can also be used as alternatives to hexavalent chromium plating. CVD can be applied to several transition metals, including tantalum (Ta) and niobium (Nb). However, these methods may require specialized equipment and expertise.

Thermal spray coating is a versatile and diverse alternative to hexavalent chromium plating, with several methods available in the market, including oxyfuel wire (OFW) spray, electric arc wire (EAW) spray, oxyfuel powder (OFP) spray, plasma arc (PA) powder spray, and high velocity oxyfuel (HVOF) powder spray.

Thermal spray coating can offer a range of properties, including corrosion resistance, wear resistance, and thermal barrier properties, depending on the coating material and method used.

The choice of an alternative to hexavalent hard chromium plating process depends on various factors, such as the application demand, cost, and the required physical characteristics. Trivalent chromium plating, vapour deposition, and thermal spray methodologies are viable alternatives to consider. However, each method has its advantages and limitations, and the final decision must be based on the specific needs of the application.

Introduction

This paper reviews two separate studies that investigate the electrodeposition of metals, specifically tin and tin-lead alloys, and their impact on the growth of tin whiskers in electronic devices.

Study 1

The first study aimed to understand the effect of adding lead to tin deposits on the growth of tin whiskers. Tin whiskers are thin protrusions that can cause short circuits and other issues in electronic devices. The study found that increasing the Pb content in the deposits alters the way copper diffuses into Sn grains, reducing the stress that could lead to whisker growth. This suggests that the intermolecular interaction between additives and surfactants can significantly affect electrodeposition processes and provide insight into the design of electrolytes for improved electrodeposition processes.

Study 2

A second study focused on the role of the intermolecular interaction between phthalic acid and non-ionic surfactant on the electrodeposition of metals. The study found that the chemical combination leads to the formation of a compact adlayer on the electrode surface, which inhibits the reduction reaction of metal ions on the cathode. The hydrophobic nature of these chemicals containing aromatic rings enhances the binding interaction and contributes to the blocking effect, which is governed by the intermolecular interaction. The study provides insight into the design of electrolytes for improved electrodeposition processes.

Methodology

Both studies analyzed matte tin electrodeposition at various Sn-Pb alloy compositions and evaluated several properties of the deposits, including crystallographic and microstructural characteristics, cathodic polarization, and the formation of Cu-Sn intermetallic compounds at the interface between the Sn or Sn/Pb films and the Cu substrate. The SEM image indicates that the deposit obtained from the electrolyte is smooth, regular, and compact. The low carbon content of the deposit suggests that the incorporation of the additive is strongly controlled in the presence of phthalic acid and non-ionic surfactant.

Conclusion

Overall, these studies provide valuable insights into the electrodeposition of metals and their applications in electronic devices. The findings can inform the design and manufacturing of electronic components, leading to more robust and reliable devices. The studies highlight the importance of intermolecular interactions between additives and surfactants in controlling the electrodeposition of metals and suggest strategies for preventing tin whisker formation in electronic devices. By understanding the mechanisms behind whisker growth, researchers and manufacturers can work towards developing more reliable electronic devices.

Note: These studies were not conducted by Advint Incorporated. Readers are required to do their own due diligence or contact Advint staff for proper technical guidance. Only use insights written by Venkat raja to gain technical knowledge.

Introduction

In metal finishing applications such as electroplating, anodizing, and electropolishing, the use of a precise and consistent power source is crucial for achieving high-quality results. The selection of the appropriate power source depends on several factors, including efficiency, reliability, and consistency of output. Two commonly used options are Insulated Gate Bipolar Transistor (IGBT) switch mode rectifiers and Silicon-Controlled Rectifiers (SCR) thyristor rectifiers. This paper aims to discuss the benefits and limitations of both options and the importance of automation in metal finishing processes.

IGBT Switch Mode Rectifiers

IGBT switch mode rectifiers are renowned for their high efficiency, rapid response time, and precise programming capabilities, which make them ideal for automated processes. They employ a high frequency switching mechanism to convert AC power to DC power, resulting in a smooth DC output. This smooth output is essential in metal finishing processes that require consistent results. The precise programming capabilities of IGBT switch mode rectifiers allow for the automation of processes, which improves the accuracy and consistency of the output. This feature is especially beneficial in processes that require high precision and consistency, such as electroplating.

IGBT switch mode rectifiers possess a compact footprint and low maintenance requirements, resulting in cost savings in the long run. Their high efficiency and rapid response time reduce power consumption, which also leads to cost savings. Automation of the process using IGBT switch mode rectifiers can further improve efficiency and reduce labor costs. These features make IGBT switch mode rectifiers a highly sought-after choice in many industries.

SCR Thyristor Rectifiers

Industry has used SCR thyristor rectifiers in electroplating applications for decades because of their high reliability and robustness. They offer a stable DC output, which is crucial in metal finishing processes where consistency is key. We achieve this stability using a thyristor device that can control the flow of electricity. The SCR thyristor rectifiers' robustness makes them suitable for harsh environments, such as those found in industrial settings.

However, SCR thyristor rectifiers exhibit lower efficiency when compared to IGBT switch mode rectifiers, resulting in higher power consumption and operating costs. This inefficiency is because SCR thyristor rectifiers use a linear voltage regulation mechanism, which leads to significant power losses. Additionally, their response time is slower than that of IGBT switch mode rectifiers, making them less suitable for processes that require high precision and rapid response time.

Selection of Power Source

The selection between IGBT switch mode rectifiers and SCR thyristor rectifiers ultimately depends on the specific requirements of the metal finishing process at hand. While both have their advantages and disadvantages, it is essential to evaluate the functions and capabilities of each technology to determine the optimal fit.

If the metal finishing process requires high precision and consistency, IGBT switch mode rectifiers are often the optimal choice because they offer superior accuracy and consistency, higher efficiency, and lower power consumption than SCR thyristor rectifiers. However, if the process involves harsh environments and requires a stable DC output, SCR thyristor rectifiers may be the better choice. The selection of the appropriate power source depends on the specific needs of the process, and the factors mentioned above should be considered when making this decision.

Importance of Automation in Metal Finishing Processes

The utilization of automation can provide several benefits in metal finishing processes, including consistent output, reduced labor costs, and increased efficiency. Ampere hour reading and the application of current during electrolysis are crucial capabilities that can be automated to improve the accuracy and consistency of the process. Automating the metal finishing process using IGBT switch mode rectifiers is especially beneficial because of their precise programming capabilities.

Advint is a well-established and reputable player in the North American rectifier procurement market. Many know the company for its expertise in fundamentals, quality, technology, and supply chain, which have contributed significantly to its success in the industry. In this article, we will delve into each of Advint's strengths and explain how they have helped the company establish itself as a reliable supplier of insulated gate bipolar transistor (IGBT) or silicon-controlled rectifier (SCR) technology for electrolytic applications.

Fundamentals

Electrolytic applications are complex processes that require careful consideration of various factors, including the conductivity and mobility of ions and the principles of Ohm's law. Advint's expertise in rectifier technology and electrochemistry enables the company to provide informed recommendations to its customers. The company's knowledge of rectifier technology helps customers select the most suitable IGBT or SCR technology for their specific needs, leading to increased productivity, reduced energy consumption, and improved overall performance. Advint's expertise is mainly valuable in electrolytic applications, where proper technology selection can make a significant difference in performance in processes such as electrolysis, electroplating, anodizing, electrowinning, and e-coat.

Quality

Advint partners with three leading rectifier manufacturers that offer certified components with automation and data integration features.

However, what sets Advint apart is its meticulous workmanship and quality system for electrolysis, hydrogenation, electroplating, and anodizing power supplies. The company's commitment to quality ensures that its rectifiers are durable and perform well under demanding conditions. This is important in electrolytic applications, where harsh conditions such as high temperatures and corrosive materials can cause equipment to fail prematurely.

Technology

Advint's expertise in electrolysis, and electricity is a critical component of its success. The company's expertise enables it to help customers achieve the best possible performance from their rectifiers. Advint can help customers select the most appropriate IGBT or SCR technology based on the specific requirements of their electrolytic applications. Besides, the company's expertise in technology allows it to develop custom solutions for its customers. Each customer's needs are unique, and Advint can work with them to develop customized solutions that meet their specific needs.

Supply Chain

Advint prioritizes the supply chain, customs clearance, and transportation, offering high-quality rectifiers at competitive prices with prompt delivery. The company's initial investment in artificial intelligence software and digital e-commerce makes the buying process convenient for customers. Advint also offers a rebate for advisory services clients who purchase rectifiers, further enhancing its customer service. This commitment to the supply chain and customer service ensures that customers receive their rectifiers when they need them.

Conclusion

Advint's strengths in the fundamentals, quality, technology, and supply chain have positioned it as a leading provider of technological advantages and cost savings in the rectifier market. The company's commitment to helping customers achieve the best possible performance from their rectifiers has helped establish its reputation as a reliable supplier of IGBT or SCR technology for electrolytic applications. If you need a reliable supplier of high-quality rectifiers for electrolytic applications, Advint is an excellent choice. The company's expertise in fundamentals, quality, technology, and supply chain ensures that customers receive the best possible products and service. Advint's commitment to its customers has helped it build a strong reputation in the industry, and the team poise to continue its success for years to come.

This article discusses the properties of nickel and cyanide ions that make them popular choices in electroplating. Nickel has high resistance to corrosion, a high melting point, and can form a strong coating on a substrate, making it suitable for a wide range of applications, including coins, jewelry, and electroplating.

Cyanide ions can form stable complexes with metal ions and dissolve any oxides or impurities on the substrate surface, allowing for better adhesion of the plated metal. However, the use of cyanide poses several risks because of its toxic nature, and alternative complexing agents such as sulfamate or gluconate are used to reduce these risks. Proper control of variables such as pH, temperature, current density, and agitation is crucial in achieving high-quality and sustainable electroplating results.

Nickel and cyanide ions play a critical role in the electroplating industry. In this article, we will explore the unique properties of nickel and cyanide ions, as well as their impact on electroplating. We commonly use Nickel in electroplating because of its ability to form a durable coating on a substrate. It is also resistant to corrosion and has a high melting point. Nickel sulfate and nickel chloride typically provide metal ions in the plating bath. Nickel has several unique properties that make it a popular choice for electroplating. It is highly resistant to corrosion, has a high melting point, and can form a strong coating on a substrate. Besides, we can easily plate nickel onto a variety of substrates, including stainless steel and nickel alloys. Nickel is a transition metal with the atomic number 28. It has a high melting point of 1,455 °C and is highly resistant to corrosion. Nickel is also a ductile metal and can form into various shapes. Because of its unique properties, nickel is widely used in the production of coins, jewelry, and electroplating.

We commonly use cyanide ions in electroplating baths because they can form stable complexes with many metal ions, including those of gold and silver. Cyanide also helps to dissolve any oxide or other impurities on the substrate surface, allowing for better adhesion of the plated metal.

However, cyanide is a toxic substance and requires careful handling and disposal. In earlier years, industry has developed alternative complexing agents that are less toxic, such as sulfamate and gluconate.

Besides the choice of cation and anion in the plating bath, other variables that can influence the quality of electroplating include pH, temperature, current density, and agitation. We must give careful consideration to these variables during the plating process to ensure consistent and high-quality results.

Overall, the influence of nickel and cyanide ions on electroplating is significant, but careful consideration must be given to achieve sustainable and high-quality results.

It is interesting to note that Donald Wood was not only instrumental in the development of nickel strike formulation but also had expertise in cyanide-based silver-plating processes. Application of a silver strike formulation with low free cyanide content shows an understanding of the potential hazards associated with cyanide in plating processes.

His comment regarding the surface scouring function of hydrogen in a strike solution highlights the importance of surface preparation in electroplating. To ensure proper adhesion and a uniform coating, the substrate surface must be clean and free of any contaminants or oxides. Strike solution, such as a nickel or silver strike, can help remove any impurities on the surface and prepare it for electroplating.

The low cathode efficiency in a strike solution allows for a liberal evolution of hydrogen, which can act as a surface scouring agent before we deposit the metal. This ensures we properly prepare the surface for the electroplating process.

Overall, Donald Wood's contributions to the surface finishing industry, including the development of Wood's nickel strike formulation, have had a significant impact on the ability to plate elements of different electromotive force potential on a variety of substrates. 

Cyanide is often used in electroplating as a complexing agent, as it can form stable complexes with many metal ions, including nickel. Cyanide can also help to dissolve any oxides or other impurities on the surface of the substrate, allowing for better adhesion of the plated metal.

However, the use of cyanide in electroplating poses several risks, as it is a toxic substance and must be handled and disposed of carefully. In addition, the use of cyanide can lead to the formation of hydrogen cyanide gas, which is highly toxic.

Other variables that can influence the quality of electroplating at the design phase include pH, temperature, current density, and agitation. Solution pH can affect the solubility and stability of the metal ions in the plating solution, while temperature can affect the rate of the plating reaction. Current density can affect the rate and distribution of metal deposition on the substrate, while agitation can help to ensure a uniform coating.

Overall, the selection of suitable cations and anions, along with careful control of variables such as pH, temperature, current density, and agitation, is critical in achieving high-quality and sustainable electroplating results. Use of complexing agents, such as sulfamate or gluconate, can also help to reduce the risks associated with cyanide use in electroplating.

In electroplating, nickel ions are used to deposit a layer of nickel on a substrate. The process involves immersing the substrate into a nickel-plating bath, which contains a solution of nickel ions. When an electric current is passed through the solution, the nickel ions are reduced and deposited onto the substrate.

Cyanide ions are often used in electroplating as a complexing agent for metal ions, including nickel. Cyanide can form stable complexes with metal ions, allowing for better adhesion of the plated metal. Besides, cyanide can help to dissolve any oxides or other impurities on the surface of the substrate, which can improve the quality of the plated metal.

However, the use of cyanide in electroplating poses several risks, as it is a toxic substance and must be handled and disposed of carefully. Cyanide can also produce hydrogen cyanide gas, which is highly toxic and poses a significant health hazard.

To reduce the risks associated with cyanide use in electroplating, alternative complexing agents such as sulfamate or gluconate can be used. These complexing agents are less toxic than cyanide and do not produce hydrogen cyanide gas.

An Idea in Brief:

In summary, nickel and cyanide ions play a critical role in the electroplating industry. Nickel possesses unique properties that make it a popular choice for electroplating, while we often use cyanide to improve the quality of the plated metal.