Page 13 - Shimadzu Journal vol.6 Issue1

Selection 5 Material Science
Ultrasonic Fatigue Testing of Metal Materials
Generally it is known that with most structural metal materials the fatigue strength lowers until a load is applied 10 times, and
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from 10 times onward the fatigue limit is reached, at which no fatigue fracture will occur. However, it is also revealed that with
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highstrength metal materials that are hardened or surface treated, internal inclusions become an origin of a fatigue fracture and
cause a fracture even at 10 to 10 cycles. On the other hand, recently, the functionality and endurance required for industrial
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products are becoming stringent, and according to this trend, metal materials forming industrial products must also meet rigorous
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requirements. Therefore, conventional testing with a maximum of 10 loading cycles is now insufficient, and a fatigue test
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exceeding 10 cycles has become required. However, such a fatigue test will take considerable time. For example, a test with 10
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cycles at a frequency of 10 Hz theoretically requires about 3.2 years. The ultrasonic fatigue testing system used for this experiment
enables testing at a frequency of 20 kHz, achieving a test with 10 cycles in about 14 hours. Therefore, this testing system is a very
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effective measurement system for fatigue tests exceeding 10 cycles.
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In this experiment, we used two kinds of metal specimens, SNCM439 and A6063, for testing according to WES 1112: 2017
(Ultrasonic fatigue testing method for metal materials) stipulated by the Japan Welding Engineering Society. The results are
introduced in this article.
Selection 6 Material Science
Surface Analysis of PET Film Using a Benchtop MALDI-TOF Mass Spectrometer
MALDI-TOF mass spectrometers are a mass spectrometer type that is used in a wide range of fields likewise LCMS, in terms of high
through-put and high sensitivity. These instruments have recently being utilized more and more for simple molecular weight
measurement and profiling of synthesized products and high-molecular compounds. This is because instruments of this type have
several features: singly-charged ions are generated so molecular weights can be recognized easily, the mass range is wide, and
there are many solvent options because the sample is dried before measurement. On the other hand, due to changes in social
conditions in these several years, government offices, universities, and private enterprises strongly request the reduction of costs
for both introduction and running of instruments used for such applications. The benchtop "MALDI-8020" MALDI-TOF mass
spectrometer is a new instrument that can sufficiently meet such market needs. The noteworthy point of this instrument is that it
has a shorter flight tube, which is the key feature of its small size, while retaining the performance equal to or higher than that of
a conventional model. In recent years, the usability of MS imaging using a MALDI-TOF mass spectrometer has become widely
recognized and various techniques are being developed. On the other hand, needs for examining the compounds that exist on
surfaces, rather than its "microscopic structure", are increasing in association with degradation and durability tests. This article
introduces an example of analyzing a PET film surface using the benchtop MALDI-TOF mass spectrometer "MALDI-8020".

Selection 7 Material Science
Evaluation of Photonic Materials with Biomimetic Structural Coloration
Colors occur either as pigments that absorb certain colors while reflecting/scattering others or as structural coloration caused by
microscopic structures. Many living things in the natural world produce this type of structural coloration that results in vivid colors,
including morpho butterflies, peacocks, and jewel beetles. Biomimetics is gaining attention as a field that utilizes the functions and
structures of these living things in the development of new technology and manufacturing processes by mimicking them.
In Application News No. A502, we confirmed the existence of structural coloration on a multi-layered film produced by mimicking
the wing structure of morpho butterflies, in which the coloration was caused by interference.1) The vivid colors observed on the
wings of some birds are also structural coloration. For example, the structural coloration of peacock plumage is said to originate
from the arrangement of melanin granules.2) Michinari Kohri, Associate Professor at the Division of Applied Chemistry and
Biotechnology at Chiba University's Graduate School of Engineering, has succeeded in producing highly visible structural coloration
by controlling the size, blackness, refractive index, and arrangement of melanin-mimicking particles (PSt@PSA particles) created by
coating the surface of polystyrene particles (PSt) with polydopamine (PDA), which is similar to melanin.3) This article introduces
measurements of photonic materials with structural coloration performed in cooperation with Associate Professor Michinari Kohri.

Selection 8 Material Science
X-ray Diffraction Analysis of Cement (2)
- Quantitative Analysis of Compounds Using the Rietveld Method -
Cement is manufactured through the processes of crushing and mixing raw materials, calcination, and finishing. The crushing and mixing
process uses raw materials such as limestone, clay, silica stone, and iron oxide and these materials contain alite (C3S), belite (C2S), aluminate
(C3A), and ferrite (C4AF). Since the ratios of these compounds differ according to manufacturer and product type and significantly affect
product performance, cement is analyzed using X-ray fluorescence and X-ray diffraction. However, even with X-ray diffraction, which is
capable of qualitatively analyzing powder samples, quantitative analysis of samples consisting of multiple components is known to be difficult
due to considerable overlapping of diffraction lines. This article introduces an analysis example of a cement powder sample which is known
the component composition and the ratio, using Siroquant software (Sietronics Pty. Ltd.) applying Rietvelt analysis method which is the one
of the profile fitting method. Siroquant enables identification of composition components and quantitative analysis in addition to the element
analysis using X-ray fluorescence in quality control of cement.

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