Rezumat

Laser cladding technology has emerged as an effective method for enhancing the performance of papermaking refiner blades. This study investigates the fabrication of a WC particle-reinforced Ni-based ceramic composite coating on a 65Mn steel substrate using laser cladding. The mechanical properties, wear resistance, and corrosion resistance of the coating are examined, revealing that laser cladding significantly improves the blade’s service life and operational stability.

I. Introduction

The refiner is a critical component in the pulp and papermaking process, with its blades enduring high-speed rotation and constant friction with fibers. This wear and corrosion can lead to decreased equipment efficiency and compromised pulp quality. Traditional metal blades have limitations in modern production environments. Tehnologie de placare cu laser, an advanced surface modification technique, offers a solution by depositing high-performance alloys or ceramic materials onto the substrate, significantly enhancing the wear and corrosion resistance of the blades.

II. Experimental Materials and Methods

1. Materials and Equipment

Material substrat: 65Mn Steel

Cladding Material: Ni55 nickel-based alloy powder and spherical cast WC powder (mass ratio 7:3)

Main Equipment: GKS-LC3005G laser cladding system, microhardness tester, bond strength tester, wear tester, electrochemical workstation, etc.

2. Coating Preparation Process

The process for preparing the laser cladding ceramic composite coating includes several steps:

Substrate Pretreatment: Grinding and preheating the substrate to prevent cracking

Powder Mixing and Sieving: Sizing the powders (50-150μm)

Placare cu laser: Using a laser power of 160W, scanning speed of 8mm/s, and powder feed rate of 15.5g/min

Post-Processing: Slow cooling, followed by grinding and polishing

III. Performance Testing and Results Analysis

1. Mechanical Properties

The laser cladding process significantly enhanced the microhardness and bond strength of the coating. The coating showed superior resistance to deformation and peeling, making it highly suitable for high-performance applications in the papermaking industry.

2. Wear Resistance

The wear resistance of the coated blades was substantially improved, with the average weight loss reduced to only 0.00016%, compared to 0.00057% for the uncoated blades. The WC particles reinforced the coating, effectively improving its wear resistance.

3. Corrosion Resistance

The laser-cladded coating demonstrated a positive shift in the self-corrosion potential, reducing the current density by an order of magnitude. This shift significantly improved the corrosion resistance of the blade, making it more durable in harsh operational environments.

IV. Conclusion

The WC/Ni55 composite ceramic coating created on 65Mn steel blades using placare cu laser technology provides superior hardness, bond strength, and excellent wear and corrosion resistance. This technology not only significantly extends the service life of refiner blades but also enhances their performance in high-load, high-corrosion environments. Laser cladding presents an effective method for improving the efficiency and longevity of refiner blades, offering substantial benefits to the papermaking industry.