TOP 3 MOST POPULAR RHODIUM ELECTROPLATING SOLUTIONS OF 2025

In the field of precious metal electroplating, rhodium is regarded as “the pinnacle of brilliance and durability.” With a hardness of up to 900 HV, exceptional chemical corrosion resistance, and superior reflectivity, rhodium ensures metal surfaces remain bright white, luxurious, and tarnish-free over time.By 2025, a new generation of rhodium plating electrolytes has emerged, featuring optimized electrolysis technology that enables faster plating speed, more uniform coatings, and greater cost efficiency.

Join PMAC as we explore the Top 3 Rhodium Electrolytes of 2025, trusted by leading industry professionals and manufacturers for their unmatched performance and long-lasting brilliance.

I. What is Electroplating?

Electroplating is the process of coating a thin layer of metal onto the surface of another material using either an electrochemical or chemical method. This technique enhances a product’s appearance, corrosion resistance, hardness, and durability.

– Basic Principle of the Electroplating Process:

In electroplating, the object to be plated acts as the cathode (negative electrode), while the plating metal serves as the anode (positive electrode). When a direct current (DC) passes through an electrolyte solution containing metal ions, these ions migrate and deposit evenly onto the surface of the substrate. The result is a bright, uniform, and firmly bonded metallic coating that improves both functional and aesthetic qualities

II. International Standard Electroplating Process

The electroplating process following international standards such as ISO 4527, ASTM B700, and ISO 6158 ensures consistent coating quality, excellent adhesion, uniform thickness, and environmental safety. Below are the key stages of a standard global electroplating workflow:

Figure 1: Shiny products after electroplating

– Step 1: Surface Preparation

Surface treatment is the most critical stage in the entire electroplating process.

Before plating begins, the metal surface must be thoroughly cleaned using specialized degreasing and pickling chemicals to remove oil, rust, dirt, and oxide layers. This step ensures an absolutely clean, smooth surface, enabling metal ions to adhere firmly during plating.

– Step 2: Surface Activation

After cleaning, the substrate is immersed in an activation solution containing specific chemical agents. This removes any remaining thin oxide films and activates the metal surface, allowing metal ions to deposit evenly and securely during the plating process.

– Step 3: Metal Deposition (Electroplating)

The plating process takes place in an electrolytic bath, where the anode is the plating metal (e.g., gold, silver, nickel, chromium, zinc), and the cathode is the substrate.

Under direct current or chemical reaction (in the case of electroless plating), metal ions migrate and deposit onto the substrate surface, forming a uniform, glossy, and precisely controlled coating that meets technical specifications for thickness, brightness, and color consistency.

– Step 4: Post-Treatment

Once plating is complete, the product undergoes several post-processing stages, including rinsing with deionized water, anti-oxidation coating, and drying at 60–80°C to remove moisture. Additional mechanical or chemical polishing may be performed to achieve a mirror-like finish that meets high aesthetic and performance standards.

– Step 5: Quality Inspection and Certification

The final stage involves rigorous quality testing based on international standards.

Key parameters evaluated include coating thickness, adhesion strength, corrosion resistance, and surface uniformity. Only products that meet all quality criteria proceed to market or export.

Coating thickness is typically verified using XRF (X-ray fluorescence) or X-ray measurement systems, ensuring every finished product delivers superior durability, visual consistency, and eco-friendly performance.

III. Top 3 hóa chất xi mạ Rhodium được ưa chuộng nhất 2025

Figure 2: Three popular Rhodium electroplating chemicals currently in use

1. RHODUNA®-Alloy 1 Rhodium-Ruthenium Electrolyte

RHODUNA®-Alloy 1 is the world’s first alloy electrolyte that combines two precious metals — Rhodium (Rh) and Ruthenium (Ru) — to deliver a coating that offers the brilliance of pure Rhodium with superior durability, wear resistance, and uniformity. Key Technical Advantages:

– Optimized composition: Contains 1.6 g/l Rhodium and 0.4 g/l Ruthenium, producing a bright white, mirror-like finish that matches pure Rhodium in color stability and brilliance.

– Excellent distribution: Ensures uniform deposition even on complex geometries, such as fine engravings, chains, and precision jewelry parts.

– High mechanical performance: The ultrafine crystalline structure achieves a microhardness of 600–900 HV, with no cracking up to 1 μm thickness and perfect adhesion on nickel, palladium, silver, and gold substrates.

– Cost efficiency: Provides comparable aesthetics and durability to Rhodium plating at a significantly lower cost, reducing overall production expenses.

– Versatile application: Compatible with both rack plating and barrel plating systems, making it ideal for jewelry, watch components, and decorative metal finishing.

2. RHODUNA® Diamond Bright Rhodium Electrolyte

RHODUNA® Diamond Bright delivers brilliant-white, diamond-like coatings with an unmatched level of brightness and reflectivity. Engineered with advanced electrochemical technology, it ensures high plating speed, excellent throwing power, and exceptional adhesion, even on intricate surfaces. Key Technical Advantages:

– Ultra-pure coating (99.99% Rhodium): Produces an intensely bright, pure-white finish with mirror-level gloss and outstanding color stability. Coating thicknesses of up to 5 μm can be achieved crack-free.

– Superior hardness and durability: With a microhardness of 800–900 HV, the coating provides excellent abrasion resistance and superior corrosion protection, even under demanding conditions.

– Direct plating capability: Can be directly deposited onto silver, gold, copper, nickel, and their alloys — eliminating the need for an intermediate strike layer.

– Versatile performance: Suitable for both rack plating and barrel plating processes, offering consistent results across jewelry, watches, optical frames, and high-end technical components

3. RHODUNA® 471 Black Rhodium Electrolyte

RHODUNA® 471 Black creates a coating that ranges from anthracite grey to deep black, offering a luxurious and modern appearance — ideal for high-end jewelry and premium accessories. The product stands out with its excellent color uniformity, superior abrasion resistance, and crack-free performance even with thicker coatings.

Outstanding Features:

– Premium adjustable black tone: The shade can be adjusted from anthracite grey to deep black, perfectly matching different design requirements.

– Superior wear resistance: Exceptional durability, offering greater hardness and longevity than traditional black ruthenium coatings.

– Thick, crack-free coating up to 0.7 μm: Ensures a smooth, stable layer without cracking.

– Excellent adhesion and easy operation: Suitable for rack plating with consistent and reliable performance.

– Recommended pre-coating: For optimal durability and color depth, pre-coating with gold or rhodium is advised.

IV. Applications of Rhodium Electroplating Chemicals in Modern Industries

1. Jewelry Manufacturing

Rhodium plating chemicals are considered the “premium standard” in the jewelry industry. A Rhodium-plated surface delivers exceptional brightness, tarnish resistance, and superior scratch protection compared to pure gold or silver. Thanks to its long-lasting color stability and hypoallergenic properties, Rhodium is often used as the final coating layer for rings, necklaces, earrings, and luxury watches — giving jewelry a brilliant, pure, and timeless finish.

2. Electronics Manufacturing

Rhodium is widely applied in plating electrical contacts and connectors (such as relays, contact pins, and terminals) due to its excellent conductivity and outstanding oxidation resistance. The Rhodium layer minimizes contact resistance, extends component lifespan, and ensures stable signal transmission in precision electronic devices such as smartphones, circuit boards, sensors, and medical electronics.

3. Automotive and Mechanical Engineering

In the automotive industry, Rhodium is used to plate interior components and sensor parts to enhance wear resistance and durability. Additionally, Rhodium plating plays a crucial role in catalytic converters, helping to reduce harmful exhaust emissions. The Rhodium coating protects metal components from corrosion and ensures long-term stability in harsh environmental conditions.

4. Medical Industry

In the medical and optical fields, Rhodium is highly valued for its chemical inertness, oxidation resistance, and excellent biocompatibility. Rhodium coatings are commonly applied to surgical instruments, micro-gripping tools, X-ray probes, and dental mirrors — providing corrosion protection, easy sterilization, and lasting brightness throughout extended use.

Figure 3: Applications of electroplating chemicals in various industries

V. Where to Buy Reliable Rhodium Electroplating Chemicals

1. Key Criteria for Selecting a Trusted Supplier

When choosing a supplier for electroplating chemicals, it’s essential to consider the following factors to ensure coating quality, process safety, and production efficiency:

– Product Quality and International Standards: Chemicals should have clearly defined specifications, verified origins, and precise concentrations of precious metals or alloys as stated by the manufacturer.

– Technical Performance and Stability: The electrolyte must deliver uniform coating thickness, consistent brightness, and strong adhesion on multiple base materials (such as gold, silver, copper, or nickel). Operating parameters like temperature, pH, and current density should be transparent and standardized.

– Technical Support and After-Sales Service: A qualified supplier should provide consultation on product selection, setup guidance, operational training, troubleshooting, and ongoing maintenance support.

– Reputation and Certification: Partner only with suppliers who represent international brands, have official distribution rights, and maintain a strong customer portfolio with proven performance.

– Safety and Environmental Compliance: Electroplating chemicals must meet environmental regulations, include proper safety data sheets (SDS), and be transported and handled under certified chemical safety standards.

– Competitive and Transparent Pricing: Choose partners offering fair pricing, timely delivery, and appropriate packaging solutions for precious metals and specialized chemicals.

2. Certified International Supplier – PMAC Corporation

PMAC Corporation is recognized as a leading and highly trusted supplier of precious metal electroplating chemicals in Vietnam and across Southeast Asia.

– Official Representative of Umicore: PMAC is the exclusive representative of Umicore, a globally renowned brand in the field of precious metal chemistry and electroplating technologies.

– International Quality Commitment: PMAC brings state-of-the-art plating solutions and globally certified chemical systems to the Vietnamese market, ensuring consistent performance and compliance with ISO and ASTM standards.

– Comprehensive Product Range and Technical Services: The company supplies a full portfolio of precious metal electrolytes — including Rhodium (Rh), Palladium (Pd), Platinum (Pt), and Gold (Au) — and provides consulting, technical support, and process optimization services tailored to each customer’s needs.

Conclusion

In the era of Industry 4.0 and the growing trend of luxury product personalization, Rhodium electroplating chemicals are no longer just surface protection materials — they have become a defining factor of value, craftsmanship, and prestige.

With exceptional corrosion resistance, brilliant white reflectivity, high hardness, and long-lasting durability, Rhodium has earned its reputation as the “gold standard” in modern electroplating technology.

The Top 3 Rhodium plating solutions — RHODUNA®-Alloy 1, RHODUNA® Diamond Bright, and RHODUNA® 471 Black — represent the next generation of electroplating innovation. These advanced electrolytes help manufacturers maximize efficiency, reduce production costs, and enhance surface quality to international professional standards.

To achieve the best plating results, selecting a trusted chemical supplier is crucial. PMAC, the official representative of Umicore (Belgium) in Vietnam, is a reliable partner delivering comprehensive precious metal plating solutions that meet global standards, while ensuring safety and environmental sustainability.