The Influence of Laser Surface Remelting on the Microstructure of EN AC-48000 Cast Alloy

Abstract Paper present a thermal analysis of laser heating and remelting of EN AC-48000 (EN AC-AlSi12CuNiMg) cast alloy used mainly for casting pistons of internal combustion engines. Laser optics were arranged such that the impingement spot size on the material was a circular with beam radius rb changes from 7 to 1500 μm. The laser surface remelting was performed under argon flow. The resulting temperature distribution, cooling rate distribution, temperature gradients and the depth of remelting are related to the laser power density and scanning velocity. The formation of microstructure during solidification after laser surface remelting of tested alloy was explained. Laser treatment of alloy tests were perform by changing the three parameters: the power of the laser beam, radius and crystallization rate. The laser surface remelting needs the selection such selection of the parameters, which leads to a significant disintegration of the structure. This method is able to increase surface hardness, for example in layered castings used for pistons in automotive engines.

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Improvement in wear resistance of hyper-eutectic AlSi cast alloy by laser surface remelting

Surface and Coatings Technology ◽

10.1016/s0257-8972(03)00100-2 ◽

2003 ◽

Vol 169-170 ◽

pp. 468-471 ◽

Cited By ~ 62

Author(s):

S. Tomida ◽

K. Nakata ◽

S. Shibata ◽

I. Zenkouji ◽

S. Saji

Keyword(s):

Wear Resistance ◽

Cast Alloy ◽

Laser Surface ◽

Laser Surface Remelting

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Surface Treatment of AISI M2 Tool Steel by Laser Melting

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.786.128 ◽

2018 ◽

Vol 786 ◽

pp. 128-133 ◽

Cited By ~ 1

Author(s):

Mohamed Newishy ◽

Hamed Abdel-Aleem ◽

M.R. Elkousy ◽

Iman El-Mahallawi ◽

A. El-Batahgy

Keyword(s):

Tool Steel ◽

High Speed ◽

Laser Scanning ◽

Laser Energy ◽

Surface Hardness ◽

Laser Surface ◽

Wear Properties ◽

Scanning Velocity ◽

Heating Source ◽

Melted Zone

Attempt was made to improve the surface hardness and wear properties of AISI M2 high speed tool steel. Laser surface melting (LSM) of tool steel was conducted with 2.2 KW Nd:YAG laser as heating source. Conventional hardening of the tool steel was applied. Characterizing the LSM, with optical and field emission scanning electron microscopy and surface hardness technique was used to evaluate the micro-hardness and mechanical behaviour of different regions of melting pool. AISI M2 tool steel is approximately HV 260, hardness after conventional treatment was 850 HV and the hardness after laser surface heat treatment is around 900 HV. It was found that there is a considerable influence of the laser power density and scanning velocity on the melted zone dimensions and the re-solidified structure. Increasing laser energy and reducing the laser scanning rate results in deeper and wider melt pool formation.

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Severe plastic deformation of Al-1%Cu Alloy processed by a Simple Cyclic Extrusion Compression technique

International Journal of Computational Physics Series ◽

10.29167/a1i1p77-90 ◽

2018 ◽

Vol 1 (1) ◽

pp. 77-90

Author(s):

Walaa Abdelaziem ◽

Atef Hamada ◽

Mohsen A. Hassan

Keyword(s):

Mechanical Properties ◽

Plastic Deformation ◽

Severe Plastic Deformation ◽

Deformation Behavior ◽

Cast Alloy ◽

Surface Hardness ◽

Grain Structure ◽

Compression Technique ◽

Cu Alloy ◽

Cyclic Extrusion Compression

Severe plastic deformation is an effective method for improving the mechanical properties of metallic alloys through promoting the grain structure. In the present work, simple cyclic extrusion compression technique (SCEC) has been developed for producing a fine structure of cast Al-1 wt. % Cu alloy and consequently enhancing the mechanical properties of the studied alloy. It was found that the grain structure was significantly reduced from 1500 µm to 100 µm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of the as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. Also, cyclic extrusion deformation increased the surface hardness of the alloy by 49 % after two passes. FE-simulation model was adopted to simulate the deformation behavior of the material during the cyclic extrusion process using DEFORMTM-3D Ver11.0. The FE-results revealed that SCEC technique was able to impose severe plastic strains with the number of passes. The model was able to predict the damage, punch load, back pressure, and deformation behavior.

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