Journal of Smart Processing
Online ISSN : 2187-1337
Print ISSN : 2186-702X
ISSN-L : 2186-702X
Current issue
Showing 1-3 articles out of 3 articles from the selected issue
  • Koki NONAKA, Soshu KIRIHARA
    2019 Volume 8 Issue 4 Pages 147-150
    Published: 2019
    Released: July 19, 2019
    JOURNALS RESTRICTED ACCESS
    A novel additive manufacturing technique was developed to create ceramic components using ultraviolet laser lithography. Twodimensional cross-sectional patterns were created through dewaxing by ultraviolet laser drawing on spread resin paste including ceramic nanoparticles, and three-dimensional composite models were sterically printed by layer lamination though powder sintering. Alumina particles with average diameter of 500 nm were dispersed in liquid resins at 60% volume fraction. The paste was spread on a glass substrate at 100 μm layer thickness. Perhaps you mean “An ultraviolet laser beam with wavelength of 355 nm and diameter of 100 μm was used to scan the pasted resin surface at speeds of 100 to 200 mm/s. Irradiation power was changed from 700 to 800 mW. Numerical lattice dimensions in the obtained geometric patterns and material microstructures in alumina components were measured and observed by digital optical and scanning electron microscopies. Alumina microlattices with 97.4% sintered density were obtained through optimized laser drawing. Fine alumina microstructures without cracks or pores were obtained through heat treatment at 1300℃ for 2 h after laser lithography. The relative density reached 99.5%. The measured dimensions of microlattices were compared with the numerical data of the original graphic design. The average dimensional tolerance was within 5 μm.
    Download PDF (923K)
  • Jongyeong OH, Takuya ISHIMOTO, Shi-hai SUN, Takayoshi NAKANO
    2019 Volume 8 Issue 4 Pages 151-154
    Published: 2019
    Released: July 19, 2019
    JOURNALS FREE ACCESS
    Selective laser melting(SLM)is a type of additive manufacturing(AM)process that can produce functional parts with complicated 3-D structures from various types of metals. Recent studies have revealed that SLM can be a potential tool not only for shape control, but also for control of the crystallographic texture of metallic materials. Texture control of refractory metals and biomaterials is an important strategy to improve their functionality. Modern SLM devices are capable of high output and can melt refractory metals that generally exhibit high melting points. In this study, we undertook the fabrication of tantalum, a typical refractory metal, through SLM and investigated its crystallographic texture formation. Tantalum parts that were nearly completely dense with a relative density of more than 99 vol.% and specific crystal orientation of <111> fiber- like texture along the building direction were developed.
    Download PDF (1470K)
  • Taiki TSUCHIYA, Yuki MAKITA, Seungwon LEE, Seiji SAIKAWA, Susumu IKE ...
    2019 Volume 8 Issue 4 Pages 155-159
    Published: 2019
    Released: July 19, 2019
    JOURNALS FREE ACCESS
    Al-Si-Mg casting alloys are widely used as practical materials due to their g ood castability, pressure resistance, corrosion resistance and excellent mechanical properties. Many researches have investigated about Al-Si-Mg casting alloy for improving the properties mentioned above. However, few reports are available about precipitation sequence and types of precipitates using transmission electron microscopy(TEM). Previously, we have reported the age-hardening of Al-10mass%Si-0.3mass%Mg alloy from the aspect of mechanical property improvement. It is needed to investigate the shape of precipitate, the distribution of precipitate and the structure of precipitate to understand precipitation hardening of Al-Si-Mg casting alloys. In this research, Al- 7mass%Si-0.3mass%Mg alloy was selected and investigated due to chemical composition similarity of A356. Alloy was prepared by casting and demolded at 773 K. Then, ice-water quenched. Aging treatment was conducted at the temperature of 473 K and 20 Hv of age-hardenability was obtained. With TEM observation, several precipitates were observed during aging treatment. Close inspection of SAED pattern and inverse fast Fourier transformation(IFFT)confirmed parallelogram type precipitate, Type-A precipitate, β’ precipitate, and Si phase.
    Download PDF (1512K)
feedback
Top