Type

Journal Article

Authors

M. Rosso
Sumsun Naher
Dermot Brabazon
M. Maurel
S.N. Aqida

Subjects

Engineering

Topics
annealing and die material heat affected zone materials micro hardness laser surface modification thermal stability mechanical engineering laser glazing

Thermal stability of laser treated die material for semi-solid metal forming (2009)

Abstract This paper presents laser surface modification work performed to improve the lifetime of die materials. Die material AISI H13, with typical hardness in the range of 42 to 48 HRC, offers high wear and corrosion resistance. However the cyclic high temperature conditions along with exposure to high viscosity molten metal in semi-solid forming cause the die to wear and crack with resultant shortened die lifetime. In this study, the thermal stability of die material at elevated temperature was investigated through micro-hardness testing and a metallographic study. AISI H13 samples were laser glazed using CO2 continuous wave mode laser with 10.6 ┬Ám wavelength. Samples were attached to a specially designed rotating chuck to enable it to be rotated at speeds up to 1500 rpm and allow flat surface glazing to take place. The micro-hardness was measured for as-glazed samples and annealed samples which were held at temperatures ranging from 550oC to 800oC with 50oC intervals. The metallographic study conducted examined the formation of three zones at different depths which were the glazed zone, the heat affected zone and the substrate. As a result of rapid heating and cooling from the laser glazing process, a metallic glass layer was developed which exhibited an average micro-hardness of 900 HV when exposed to 3.34E+10 W/m2 laser irradiance within a range of 3.64 to 5.66 ms exposure time. Crystallization in glazed zone increased as the annealing temperature increased. As the annealing temperature reached above approximately 600oC, the micro-hardness decreased to approximately 600 HV (equivalent to approx. 54 HRC) due to local crystallization. These findings show potential direct application of glazed dies for non-ferrous semi-solid forming and the requirement for thermal barrier protection for application at higher temperatures.
Collections Ireland -> Dublin City University -> Publication Type = Article
Ireland -> Dublin City University -> DCU Faculties and Centres = DCU Faculties and Schools
Ireland -> Dublin City University -> Status = Published
Ireland -> Dublin City University -> DCU Faculties and Centres = DCU Faculties and Schools: Faculty of Engineering and Computing: School of Mechanical and Manufacturing Engineering
Ireland -> Dublin City University -> Subject = Engineering: Mechanical engineering
Ireland -> Dublin City University -> DCU Faculties and Centres = DCU Faculties and Schools: Faculty of Engineering and Computing
Ireland -> Dublin City University -> Subject = Engineering: Materials
Ireland -> Dublin City University -> DCU Faculties and Centres = Research Initiatives and Centres: Materials Processing Research Centre (MPRC)
Ireland -> Dublin City University -> Subject = Engineering
Ireland -> Dublin City University -> DCU Faculties and Centres = Research Initiatives and Centres

Full list of authors on original publication

M. Rosso, Sumsun Naher, Dermot Brabazon, M. Maurel, S.N. Aqida

Experts in our system

1
Sumsun Naher
Dublin City University
Total Publications: 56
 
2
Dermot Brabazon
Dublin City University
Total Publications: 162