Solvothermal Modified Layers against High Temperature Corrosion

Abstract

Service and downtimes of waste incineration plants generate high expenses for their operators. State of the art is to protect high corrosion exposed components by cladding them with a nickel based alloy. The welded overlay is 2-3 mm thick and very expensive. It needs to be repaired at each service interval. An alternative coating consists of a thermal sprayed multilayer of a nickel based bondcoat and a ceramic topcoat. Thickness and costs of this multilayer are assumed to be in the range of about 10% of the currently used coating. A solvothermal treatment chemically densifies the coating. This leads to a significantly lower porosity whilst improving cohesion and hardness properties. This innovative process leads to a self-healing layer caused by the high temperature waste gas exposition as the driving force.

High Temperature Corrosion Studies of a Zirconia Coating: Implications for Waste-to-Energy (WTE) Plants

“…Studies from Wöllmer and coworkers [26] have shown an improved corrosion resistance of solvothermally pretreated test probes. This pretreatment might follow a routine, described herein for the lab-scale experiments.…”