Increased Wear and Oxidation Resistance of Titanium Aluminide Alloys by Laser Cladding

Abstract

A process layout for laser cladding of layers on substrates of titanium aluminides using state-of-theart and modified (additions of Si and TiB 2 ) TiAl alloys is presented. The process involves a preheating of the samples to reduce thermal stresses and cladding in an inert gas atmosphere with an oxygen content lower than 30 ppm. These conditions lead to crack free layers and low surface oxidation. Microstructure and hardness of the layers are investigated. The abrasive wear resistance of the cladded layers in comparison to the base material is tested with promising results. Finally results of the oxidation behavior are shown and prove the increased performance of modified TiAl layers in comparison to the base material.

Combinatorial Alloy Design by Laser Additive Manufacturing

“…We present a new methodology for rapid bulk alloy screening combining two metallurgical research fields, namely, Laser Additive Manufacturing (LAM) and combinatorial bulk alloy design . As an example system we investigate different alloy blends of two types of tool steels, a Cr–Mo–V hot working tool steel and a Ni‐based maraging steel .…”

“…A second advantage of using LAM for combinatorial alloy design is that it involves rapid melting and solidification with only a small melt pool volume . This offers the opportunity to also probe materials that cannot readily be cast conventionally, for example, oxide‐dispersion strengthened alloys or materials containing solute contents above the solubility limit.…”

“…This offers the opportunity to also probe materials that cannot readily be cast conventionally, for example, oxide‐dispersion strengthened alloys or materials containing solute contents above the solubility limit. Typical cooling rates encountered in LAM range from 10 3 to 10 6 K s −1 . Such high cooling rates lead to rapid solidification of the melt, yielding beneficial, very fine solidification microstructures, in contrast to the usually coarse casting microstructures obtained after the first step of conventional processing .…”

“…Laser‐based Additive Manufacturing of metallic components can be achieved either by Selective Laser Melting (SLM) or by Laser Metal Deposition (LMD) . The latter approach is sometimes also referred to as Laser Surface Cladding or Laser Cladding.…”

Alkaline corrosion properties of laser-clad aluminum/titanium coatings

“…A number of investigations that are reported in the literature on LSC (Ocylok et al, 2011;Xu et al, 2006) were related to the effect on wear or high temperature oxidation resistance. Yue et al (2006) studied LSC coatings on AA7075 substrates with powders containing Al-0.3TiO 2 -0.3SiO 2 , Al-0.17Cr 2 O 3 -0.5SiO 2 and Al-0.375CuO-0.375SiO 2 .…”