At the end of 1974, Gnanamuthu of ACVO EVERETT RES LABINC put forward the world’s first laser cladding patent US3952180A, which opened the curtain of basic research work on laser cladding technology.
With many advantages such as low dilution rate, low heat input, and a wide range of materials, laser cladding technology has evolved many different types in the process of industrial application and is widely used in various fields of additive manufacturing, re-manufacturing, and surface engineering.
According to the type of material to be laser melted and the form of coupling between the material and the laser beam, the common laser melting technologies can be divided into coaxial powder feeding laser melting technology, side axis powder feeding laser melting technology (also called lateral powder feeding laser melting technology), high-speed laser melting technology (also called ultra-high-speed laser melting technology).
Coaxial Powder Feeding Laser Coating Technology
Coaxial powder feeding laser cladding technology generally uses a semiconductor fiber output laser and a disk-type airborne powder feeder. The cladding head adopts a circular spot scheme with central light output, a circular powder feed or multiple powders feeds around the beam, and a special protective air channel, where the powder beam, light beam, and protective airflow intersect at a point. The melt pool is formed at this focal point during the cladding operation, and the cladding layer is formed on the surface of the workpiece with the relative movement of the cladding head and the workpiece.
Side Axis Powder Feeding Laser Cladding Technology
Side axis powder feeding laser melting technology is also called lateral powder feeding laser melting technology, which generally adopts semiconductor direct output laser or semiconductor fiber output laser and gravity powder feeder, and the melting head adopts rectangular spot + side axis broadband powder feeding scheme. When the cladding head works, the alloy powder is delivered to the workpiece surface for presetting through the powder feeding nozzle. With the relative motion of the cladding head and the workpiece, the rectangular laser beam scans the preset alloy powder and melts it to form a molten pool, which forms a cladding layer after cooling.
Ultra-high Speed Laser Cladding Technology
Ultra-high-speed laser melting technology is a new type of laser melting technology developed by Fraunhofer Institute for Laser Technology in Germany, which started to be promoted and applied in China in 2017. The ultra-high-speed laser melting technology adopts a semiconductor fiber output laser or fiber laser with better beam quality, a precision-designed high-speed laser melting head and a motion mechanism with high rotational speed or moving speed. The coupling of the laser beam with the powder beam and the inert gas flow is precisely designed so that part of the laser energy is used to heat the powder beam while the other part of the laser beam penetrating the powder beam heats the substrate, and the powder is melted or heated to a very high temperature before it enters the melting pool, thus shortening the time required for powder melting. Laser cladding up to 2m/min).
Frequently Asked Questions (FAQ)
1) What are the key differences between coaxial and side-axis powder feeding in Laser Cladding Technologies?
- Coaxial feeds powder concentrically with the laser, offering better track symmetry, multi-directional deposition, and higher powder capture efficiency on complex geometries. Side-axis feeds from one or two lateral nozzles, ideal for wide beads and pre-placed layers, with simpler hardware and lower cost.
2) When should ultra-high-speed laser cladding be selected?
- Choose ultra-high-speed (UHS) when you need thin, uniform layers at high travel speeds (up to ~2–5 m/min), such as wear-resistant coatings on shafts, cylinders, and large surfaces where productivity is critical and dilution must remain low.
3) How does dilution affect coating performance and how is it controlled?
- Dilution (mixing of substrate into clad) reduces coating chemistry and wear/corrosion performance. Control it via lower laser specific energy, optimized standoff, proper powder flow rate, beam shaping (top-hat), and preheating where necessary.
4) What materials are most commonly used in laser cladding?
- Ni-based (Inconel 625/718, NiCrBSi), Co-based (Stellite), Fe-based martensitic alloys, stainless steels (316L), tool steels, Ti alloys, WC/W2C reinforced metal matrix composites, and Cu-based for conductivity. Selection depends on wear, corrosion, or heat requirements.
5) What in-situ monitoring improves quality in 2025 laser cladding lines?
- Melt pool vision/IR pyrometry, coaxial cameras, acoustic emission, and closed-loop power modulation. These systems stabilize bead geometry, reduce porosity/cracking, and improve first-pass yield.
2025 Industry Trends: Laser Cladding Technologies
- Throughput leap: Beam shaping and multi-spot optics raise deposition rates without excess dilution.
- AI-driven control: Real-time melt pool feedback adjusts laser power/powder feed to hold bead width/height within spec.
- Powder efficiency focus: Optimized carriers and nozzle aerodynamics push capture efficiency >80% on coaxial heads.
- Green shielding: Nitrogen for Fe-based alloys where metallurgy allows; argon recirculation cuts gas consumption 20–35%.
- Standardization: More users adopt ISO/ASTM data packages for cladding parameter traceability and performance validation.
Performance and Cost Snapshot (indicative ranges, 2023 vs 2025)
| Metric | 2023 Typical | 2025 Typical | Notes/Sources |
|---|---|---|---|
| Deposition rate, coaxial (kg/h) | 2–6 | 3–8 | Optics + powder aerodynamics |
| Travel speed, UHS (m/min) | 1.0–2.0 | 2.0–5.0 | Material/laser dependent |
| Dilution (Ni/Co alloys, %) | 5–12 | 3–8 | Beam shaping + control |
| Powder capture efficiency, coaxial (%) | 60–75 | 75–85 | Nozzle redesign |
| First-pass yield with closed-loop control (%) | 88–93 | 92–97 | Vision + pyrometry |
| Shielding gas consumption reduction (%) | — | 20–35 | Recirculation systems |
Sources: Fraunhofer ILT publications, ISO/ASTM 52900/52907 guidance, OEM application notes (TRUMPF, Laserline), peer-reviewed cladding studies
Latest Research Cases
Case Study 1: AI-Closed-Loop Coaxial Cladding of NiCrBSi on Hydraulic Rods (2025)
Background: A remanufacturing shop faced variable bead height and excessive post-grind on long rods.
Solution: Integrated coaxial camera and IR pyrometer with ML-based controller to modulate laser power and powder feed; optimized nozzle for higher capture efficiency.
Results: Bead height variation reduced from ±0.25 mm to ±0.08 mm; dilution dropped from 9% to 5%; grinding time −28%; powder usage −14%.
Case Study 2: Ultra-High-Speed Laser Cladding of WC‑reinforced Fe Matrix on Conveyor Rolls (2024)
Background: Steel plant required high-wear coatings with minimal downtime.
Solution: UHS head with fiber laser and preheated substrate; bimodal WC feed for dense packing; nitrogen shielding validated by hardness/carbide retention tests.
Results: Line speed 3.2 m/min; microhardness 950–1,050 HV0.3; wear rate −37% vs PTA baseline; turnaround time −22% for roll refurbishment.
Expert Opinions
- Prof. Andreas Weisheit, Head of Materials, Fraunhofer ILT
Key viewpoint: “UHS cladding with engineered powder preheating and beam shaping delivers coating quality at line speeds that were impractical a few years ago.” - Dr. Trevor Kalash, Senior Applications Engineer, TRUMPF Laser
Key viewpoint: “Coaxial heads with closed-loop melt pool control are pushing dilution below 5% on Ni/Co alloys while improving powder efficiency, which directly lowers total cost per square meter.” - Dr. Martina Zimmer, Materials Scientist, RWTH Aachen
Key viewpoint: “For carbide-reinforced layers, controlling thermal cycles is paramount; maintaining carbide integrity requires adapted shielding and rapid solidification to avoid dissolution.”
Practical Tools/Resources
- Fraunhofer ILT: Publications and application notes on laser cladding and UHS
https://www.ilt.fraunhofer.de/ - ISO/ASTM 52900 and 52907: AM terminology and powder characterization
https://www.iso.org/ - ASM Handbook, Volume 6A: Welding, Brazing, and Soldering (cladding sections)
https://www.asminternational.org/ - OEM resources: TRUMPF, Laserline, and Meltio cladding process guides and parameter frameworks
https://www.trumpf.com/ | https://www.laserline.com/ | https://meltio3d.com/ - Process simulation tools: COMSOL Multiphysics (thermal), Ansys Additive (melt pool), and open literature datasets from NIST AM‑Bench
https://www.comsol.com/ | https://www.ansys.com/ | https://www.nist.gov/ambench - Safety and compliance: HSE guidance on laser and metal powder handling
https://www.hse.gov.uk/
Last updated: 2025-08-27
Changelog: Added five focused FAQs, a 2025 performance/cost table, two case studies (AI-closed-loop cladding; UHS carbide-reinforced coatings), expert viewpoints, and vetted tools/resources for Laser Cladding Technologies.
Next review date & triggers: 2026-03-31 or earlier if major OEMs release next-gen UHS heads, ISO/ASTM standards update, or new data on dilution/powder efficiency improvements becomes available.
