Thursday, September 28, 2023
SCIENMAG: Latest Science and Health News
No Result
View All Result
  • Login
  • HOME PAGE
  • BIOLOGY
  • CHEMISTRY AND PHYSICS
  • MEDICINE
    • Cancer
    • Infectious Emerging Diseases
  • SPACE
  • TECHNOLOGY
  • CONTACT US
  • HOME PAGE
  • BIOLOGY
  • CHEMISTRY AND PHYSICS
  • MEDICINE
    • Cancer
    • Infectious Emerging Diseases
  • SPACE
  • TECHNOLOGY
  • CONTACT US
No Result
View All Result
Scienmag - Latest science news from science magazine
No Result
View All Result
Home SCIENCE NEWS Technology and Engineering

Professor Li Faxin’s group develops world’s first DMA for hard materials

December 17, 2021
in Technology and Engineering
0
Share on FacebookShare on Twitter

Recently, the Li Faxin Research Group of Peking University College of Engineering developed the world’s first dynamic mechanical analyzer (DMA) suitable for hard materials (metals, ceramics, etc.), as shown in Figure 1 below. The instrument is based on the electro-mechanical impedance method which can quickly, accurately, and automatically measure  Young’s modulus, shear modulus, and corresponding internal friction of materials under variable temperature conditions. The advent of the instrument has brought good news to the high and low-temperature mechanical analysis in the fields of superalloys (ceramics), composites, functional materials, and amorphous alloys. It also means that China has achieved an internationally leading position in this field. The first author to complete the work is Xie Mingyu, a 2018 doctoral student of the same research group.

the world's first dynamic mechanical analyzer for hjard materials

Credit: Peking University College of Engineering

Recently, the Li Faxin Research Group of Peking University College of Engineering developed the world’s first dynamic mechanical analyzer (DMA) suitable for hard materials (metals, ceramics, etc.), as shown in Figure 1 below. The instrument is based on the electro-mechanical impedance method which can quickly, accurately, and automatically measure  Young’s modulus, shear modulus, and corresponding internal friction of materials under variable temperature conditions. The advent of the instrument has brought good news to the high and low-temperature mechanical analysis in the fields of superalloys (ceramics), composites, functional materials, and amorphous alloys. It also means that China has achieved an internationally leading position in this field. The first author to complete the work is Xie Mingyu, a 2018 doctoral student of the same research group.

Modulus and internal friction (or damping) are the basic physical properties of all solid materials. Their changes with temperature can accurately reflect the internal evolution of materials, such as atomic diffusion, grain boundary sliding, solid-state phase transition, etc. However, there is a lack of methods and instruments that can accurately measure material modulus and internal friction at the same time. Commercial DMA can only be used to measure polymer soft materials with small modulus and large damping, but the measurement results of hard materials are inaccurate, especially since the measurement deviation of internal friction is very large. At present, the measurement method of hard material modulus is mainly the free beam vibration method of the American ASTM standard, but the accuracy of this method is very poor. The internal friction of hard materials is mainly measured by the Ke-type pendulum method proposed by the famous metal physicist Ke Ting-sui, but this method can only measure the torsional internal friction of filament samples. Its measurement of shear modulus is not accurate, and the measurement process is cumbersome, so it is difficult to realize automatic measurement.

Prof. Li Faxin’s group proposed a modulus and internal friction measurement method based on electro-mechanical impedance method, which can accurately and quickly measure the Young’s modulus, shear modulus, and corresponding internal friction of materials (Rev SciInstrum 2020, Editor’s Pick, https://doi.org/10.1063/1.5135360;J App Phys 2020, Invited Perspective & Featured Article, https://doi.org/10.1063/5.0034801). On this basis, they realized automatic measurement, increased the measurement temperature to 1300 ⁰ C, and developed this high-temperature DMA suitable for hard materials. In fact, this method is not sensitive to temperature, as long as the temperature of the heating furnace can be reached, there is no problem if the measurement range is above 2000 ⁰ C.

Using this new DMA, the research group obtained the grain boundary sliding internal friction peak in polycrystalline pure aluminum under high-frequency vibration (tens of kHz) for the first time, and the peak temperature reached nearly 500 ⁰ C, which is much higher than the low-frequency internal friction peak (285 ⁰ C) discovered by academician Ke Ting-sui in 1947 (Xie, Li, J Alloy Comp 2021, https://doi.org/10.1016/j.jallcom.2021.159556).

Figure 2 shows the results of measuring the modulus and internal friction of TC4 titanium alloy from room temperature to 1200 ⁰ C using the new DMA. It can be seen from the figure that near 990 ⁰ C, both moduli reach the minimum and both internal friction peak, indicating that the material has undergone a solid-state phase transition (transformation from the α+β mixed phase to β phase). It can also be observed that when the material temperature rises above 700 ⁰ C, the internal friction begins to rise sharply, which indicates that the working temperature of TC4 must not exceed 700 ⁰ C. This work was recently published online in an authoritative journal in the field of metal materials (https://doi.org/10.1016/j.scriptamat.2021.114435).



Journal

Scripta Materialia

Tags: developsDMAFaxinsgrouphardMaterialsprofessorworlds
Share26Tweet16Share5ShareSendShare
  • Grape Wood Borer

    Important additional driver of insect decline identified: Weather explains the decline and rise of insect biomass over 34 years

    69 shares
    Share 28 Tweet 17
  • Null results research now published by major behavioral medicine journal

    1057 shares
    Share 423 Tweet 264
  • New study definitively confirms gulf stream weakening, understanding the changes could help predict future trends in extreme events

    68 shares
    Share 27 Tweet 17
  • New findings on hair loss in men

    81 shares
    Share 32 Tweet 20
  • Abdominal fat plays important role in remission of prediabetes

    65 shares
    Share 26 Tweet 16
  • New rooms discovered in Sahura’s Pyramid

    65 shares
    Share 26 Tweet 16
ADVERTISEMENT

About us

We bring you the latest science news from best research centers and universities around the world. Check our website.

Latest NEWS

Null results research now published by major behavioral medicine journal

New findings on hair loss in men

Important additional driver of insect decline identified: Weather explains the decline and rise of insect biomass over 34 years

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 208 other subscribers

© 2023 Scienmag- Science Magazine: Latest Science News.

No Result
View All Result
  • HOME PAGE
  • BIOLOGY
  • CHEMISTRY AND PHYSICS
  • MEDICINE
    • Cancer
    • Infectious Emerging Diseases
  • SPACE
  • TECHNOLOGY
  • CONTACT US

© 2023 Scienmag- Science Magazine: Latest Science News.

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In