Traditional surface treatment methods 

Hard chrome plating involves electroplating a thin layer of chromium onto metal surfaces, enhancing wear and corrosion resistance for applications like hydraulic cylinders and rollers. However, despite its widespread use in industries such as manufacturing or offshore, hard chrome plating is known to have several key weaknesses in demanding environments. The chromium layer is mechanically bonded, which can lead to poor adhesion and cracking under heavy loads or temperature fluctuations. Although hard chrome provides a tough outer layer, it is brittle and susceptible to peeling or flaking when subjected to impact or continuous mechanical stress, limiting its durability in demanding environments.

Hard chrome plating is also vulnerable to pitting and rust formation when exposed to moisture, particularly when the protective oil layer on cylinder rods is missing due to lack of movement, exposing the plated surface to the elements. Additionally, this process involves hexavalent chromium (Cr6). Chromium-6 is a chemical commonly used in various industrial coatings, but it is associated with serious health risks. As a result, the European Commission has significantly restricted its use, and a complete ban is expected to be imposed following the current regulations. While hard chrome can last several years under moderate conditions, it often requires frequent maintenance, such as reapplication and polishing, to maintain its protective properties in more aggressive settings.

Thermal spraying refers to a family of processes where heated or molten materials are sprayed onto a surface to create a protective coating. Used across industries such as aerospace and power generation, thermal spraying can apply coatings made of alloys, ceramics, and composites. The primary advantage of thermal spraying is its versatility, as it can coat large surface areas with relatively thick layers. However, thermal spray coatings, including plasma spraying, are typically mechanically bonded to the substrate, which means they lack the metallurgical bond that laser cladding provides. This makes them more prone to cracking, chipping, and delamination, particularly under heavy mechanical loads or thermal cycling.

While thermal spray coatings can provide excellent resistance in certain conditions, their porosity limits their effectiveness in highly corrosive environments where moisture and chemicals can penetrate, leading to potential corrosion of the underlying material. Additionally, in applications where components are exposed to both high temperatures and mechanical stress, thermal spray coatings may deteriorate more quickly than expected. Frequent inspections are essential to detect any wear or damage early on, as damaged coatings require recoating to maintain adequate protection.

Plasma spraying is a thermal spray process using a high-temperature plasma jet to melt and deposit materials onto surfaces. It is widely used for ceramic, metallic, and composite coatings in industries such as aerospace, automotive, and power generation. Plasma spraying is versatile, but like other thermal spray techniques, it relies on a mechanical bond that is prone to delamination under mechanical stress or temperature cycling.

In high-stress applications like turbine blades or engine components, plasma-sprayed coatings may crack or peel over time, especially if exposed to impact, vibration, or temperature fluctuations. The porous nature of many plasma-sprayed coatings also limits their corrosion protection, making regular maintenance and recoating necessary to maintain their effectiveness in aggressive environments.

Plasma Transfer Arc (PTA) is an advanced surface enhancement technique used to apply durable, wear-resistant coatings to metal surfaces. Utilizing a high-energy plasma arc, the PTA process melts a metallic powder or wire, creating a metallurgical bond with the substrate for a robust, long-lasting layer. Known for its strength and durability, PTA coatings are particularly suited for applications in demanding industries like oil and gas, mining, and heavy machinery,

where components are exposed to extreme wear and require exceptional protection. Although PTA provides a resilient coating, the higher heat input can lead to a broader heat-affected zone, potentially causing thermal stress or distortion in thinner materials. Additionally, PTA is typically more suited to creating thicker layers, which may lead to increased material use and less precision when applying fine or uniform coatings.