Utilisation of High-Energy Heat Sources in Magnesium Alloy Surface Layer Treatment

The main aim of the study was the evaluation of magnesium alloy surface treatment effectiveness using high-energy heat sources, i.e. a Yb-YAG Disk Laser and the GTAW method. The AZ91 and AM60 commercial magnesium alloys were subject to surface layer modification. Because of the physicochemical properties of the materials studied in case of the GTAW method, it was necessary to provide the welding stand with additional equipment. A novel two-torch set with torches operating in tandem was developed within the experiment. The effectiveness of specimen remelting using a laser and the GTAW method was verified based on macro- and microscopic examinations as well as in X-ray phase analysis and hardness measurements. In addition, the remelting parameters were optimised. The proposed treatment methodology enabled the achieving of the intended result and effective modification of a magnesium alloy surface layer.

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Structural Aspects of Remelting of the AZ91 Magnesium Alloy Surface Layer

Archives of Foundry Engineering ◽

10.1515/afe-2015-0095 ◽

2016 ◽

Vol 16 (1) ◽

pp. 13-18

Author(s):

J. Iwaszko ◽

M. Strzelecka

Keyword(s):

Surface Layer ◽

Magnesium Alloy ◽

Structural Changes ◽

Continuous Wave ◽

Sample Surface ◽

Alloy Surface ◽

Az91 Alloy ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium ◽

Alloy Surface Layer

Abstract In this study, modification of the AZ91 magnesium alloy surface layer with a CO2 continuous wave operation laser has been taken on. The extent and character of structural changes generated in the surface layer of the material was being assessed on the basis of both macro- and microscopy investigations, and the EDX analysis. Considerable changes in the structure of the AZ91 alloy surface layer and the morphology of phases have been found. The remelting processing was accompanied by a strong refinement of the structure and a more uniform distribution of individual phases. The conducted investigations showed that the remelting zone dimensions are a result of the process parameters, and that they can be controlled by an appropriate combination of basic remelting parameters, i.e. the laser power, the distance from the sample surface, and the scanning rate. The investigations and the obtained results revealed the possibility of an effective modification of the AZ91 magnesium alloy surface layer in the process of remelting carried out with a CO2 laser beam.

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Phase and structural states in the NiTi-based alloy surface layer formed by electron-ion-plasma methods using tantalum

10.1063/1.4932852 ◽

2015 ◽

Author(s):

Aleksei A. Neiman ◽

Ludmila L. Meisner ◽

Aleksandr I. Lotkov ◽

Ekaterina Y. Gudimova ◽

Viktor O. Semin

Keyword(s):

Surface Layer ◽

Alloy Surface ◽

Ion Plasma ◽

Plasma Methods ◽

Alloy Surface Layer

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Modification of Al-Si alloy surface layer using Nd:YAG laser

10.1117/12.726543 ◽

2006 ◽

Author(s):

Agnieszka E. Radziszewska ◽

Sławomir Z. Kąc

Keyword(s):

Surface Layer ◽

Nd:Yag Laser ◽

Alloy Surface ◽

Alloy Surface Layer

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Kinetics of phase transformations in a binary alloy surface layer at the selective dissolution. I. Theoretical analysis

Protection of Metals and Physical Chemistry of Surfaces ◽

10.1134/s2070205109010043 ◽

2009 ◽

Vol 45 (1) ◽

pp. 31-35

Author(s):

O. A. Kozaderov ◽

O. V. Koroleva ◽

A. V. Vvedenskii

Keyword(s):

Surface Layer ◽

Theoretical Analysis ◽

Phase Transformations ◽

Binary Alloy ◽

Selective Dissolution ◽

Alloy Surface ◽

Kinetics Of ◽

Alloy Surface Layer

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Influences of Surface Nanocrystallization Induced by High-Energy Spot Peening on Microstructure and Properties of Magnesium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2120 ◽

2013 ◽

Vol 690-693 ◽

pp. 2120-2125 ◽

Cited By ~ 1

Author(s):

Li Wen Tang ◽

Jian Sun ◽

Jin Zhang ◽

Xin Bing Ou ◽

Zhi Ming Zhou

Keyword(s):

Surface Layer ◽

Magnesium Alloys ◽

Corrosion Potential ◽

Electrochemical Measurement ◽

Corrosion Current ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Surface Nanocrystallization ◽

Grain Sizes

As relatively new structure materials, magnesium and its alloys demonstrated significant potential for applications in many industries. However, magnesium alloys were easy to be corroded which greatly limited their development. AZ31B and AZ91D, two widely used commercial magnesium alloys in various industries, were chosen to be produced nanostructure on the surface layer, called Surface Nanocrystallization (SNC) by High Energy Spot Peening (HESP). The microstructure was characterized by Scan Electronic Microscopy (SEM) and X-ray diffraction (XRD) in this paper. Microhardness and corrosion resistance were measured by microhardness tester and electrochemical measurement system respectively. Experimental results showed that after HESP the grain sizes in the surface layer were obviously reduced into nanoscale; microhardness was greatly increased in the treated surface, about two times as much as that of original and corrosion current density in polarization curve was evidently raised while corrosion potential changed little.

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