The good focusing ability of the laser allows power densities that are hardly possible with conventional thermal procedures. Thus, the desired component processing can be carried out on a limited area with low overall power – the component and the material are only subject to minimal thermal loading. Laser build-up welding is thereby particularly suitable for applications in tool and mold manufacturing, in which only minimum distortion can be tolerated, as well as for materials that are difficult to weld using conventional methods, for example, high-temperature resistant nickel-based alloys in gas turbines.

Laser metal forming i.e. build-up welding and laser cladding are related to the conventional TIG (Tungsten Inert Gas) and PTA (Plasma Transfer Arc) build-up welding processes. In place of the electric arc or the plasma, however, a laser is used as the heat source. The powdery build-up material is transported in an inert carrier gas, and is brought via a powder nozzle to the melt pool created by the laser. Our mobile 1.5 kW Fiber-Laser system can be used for on-site laser metal forming and cladding applications. Our 6-axes gantry robot with a 2 kW CO2-Laser allows laser applications on large and complex part geometries. Small repairs on precision parts as well as large parts can be done with our mobile, hand operated 150 W Nd:YAG-Laser system.

Benefits

The essential advantages of the build-up laser welding process are

• Minimal distortion due to the small, localized heat input
• Small heat affected zone, therefore minimal modification of the substrate material
• Perfect metallurgical bonding
• Surface coating as well as weld build-up of edges
• Near net-shape welding, less finishing effort
• Broad range of build-up materials
• Joining of difficult combinations of materials

Examples Laser Metal Forming LMF

Sulzer Innotec has a long lasting experience in the laser weld repair of blade sets from industrial gas turbines (IGTs). It also successfully participates in international research projects that focus on the repair of single crystal blades.

Tip welding	Reconstruction/modification of worn areas	Blade root repair

Repair orders for mold tools are announced at short notice and need immediate processing. The build-up welding on large or complex surfaces needs time and is done under full CNC-control.

Knife edge weld build-up 200 x 10 x 10 mm	Correction of a curved geometry with undersize, 0.7 mm thickness	Precision build-up, 0.25 mm thickness

Examples Laser Cladding LC

The blades in the rear stages of a steam turbine are affected by droplet erosion. One solution to avoid this problem is the Stellit™ cladding of the blade leading edge. Compared to conventional brazing technologies there is a life-time advantage, the perfect metallurgical bonding of the welded Stellit™ layer avoids delamination.

Stellite™ coating on the blade leading edge for droplet erosion protection	Stellite™ coating on a valve body

Typical Materials

Ni-base alloys	IN718, IN738, IN792, IN939, MarM247, CMSX-2, CMSX-4, PWA1480, Nimonic 80A
Related filler materials	N625, IN718, IN738, MarM509, CMSX-2, CMSX-4
Stainless steals	1.4021, 1.4301, 1.4310, 1.4313, 1.4435, 1.4550, 1.4571, 1.4404, 18/12, et al.
Alloyed tool steels	1.2083 (X42Cr13), 1.2343 (X38CrMoV5-1), 1.2379 (X155CrVMo12-1), et al..
Typical filler material	1.2083 (X42Cr13)
Coatings	Stellite6, Stellite694, et al., special compositions

Our Partners

Highly qualified experts at Sulzer Innotec are our partners for

• One-stop-shop manufacturing solutions, manufacturing and welding engineering and consulting
• Mechanical precision workshop and prototyping
• Conventional welding processes and heat treatment
• Testing and metrology
• Material and surface technology
• Corrosion and corrosion protection, friction and abrasion
• Material and failure analysis