Manufacture of Layers Filled with Hard Material Using CO2 Laser Beams

Abstract

The two Ferro-Titanit grades “WFN” and “C-Spezial” with different Ms, f-temperatures were produced as conveyable powders in which finest-grained carbide, making up 50 % by volume, is surrounded by a martensitic hardenable matrix. Coating was made by atmospheric plasma spraying (APS) and partial vacuum plasma spraying (VPS), the layers being treated subsequently by means of a 5 kW-laser. Substrates used were: S 6-5-2 (Thyrapid 3343) — hardened and tempered, X 2 NiCoMoTi 12 8 8 (Thyrotherm 2799) — solution annealed and aged, X 5 CrTi 12 (Remanit 4512), sintered Ferro-Titanit material grade WFN — hardened and tempered and X 35 CrMoV 5 11 (Thyrotherm 2342) — annealed: The formation of cracks could only be avoided by VPS layers with the combinations C-Spezial/X 5 CrTi 12, WFN/X 2 NiCoMoTi 12 8 8, WFN/X 5 CrTi 12 and WFN/X 35 CrMoV 5 11. It can be concluded that as a rule the matrix of a layer should have the lowest possible Ma.f -temperatures the tool-steel substrate the highest possible Ms, f-temperatures.