Microstructural analysis by scanning thermal microscopy of a nanocrystalline Fe surface induced by ultrasonic shot peening

2004 ◽  
Author(s):  
F GUO
Keyword(s):  
Shot Peening ◽  
Microstructural Analysis ◽  
Scanning Thermal Microscopy ◽  
Thermal Microscopy ◽  
Ultrasonic Shot Peening

Enhancement in Fatigue Life of Ti-13Nb-13Zr Alloy through Ultrasonic Shot Peening

2019 ◽  
Vol 813 ◽  
pp. 122-128
Author(s):  
Pramod Kumar ◽  
Girija Shankar Mahobia ◽  
Kausik Chattopadhyay
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Initiation ◽  
Shot Peening ◽  
Low Cycle Fatigue ◽  
Microstructural Analysis ◽  
Fatigue Crack Initiation ◽  
Surface Hardness ◽  
Ultrasonic Shot Peening ◽  
13Zr Alloy

β-Ti (Ti–13Nb–13Zr) alloy was subjected to ultrasonic shotpeening (USSP) and a nanocrystalline layer of ~60 µm thickness was developed on the metastable Ti-13-Nb-13Zr alloy. In this investigation, the surface hardening and low cycle fatigue (LCF) behavior of the alloy were studied after USSP treatment. Compared to the un-shotpeened samples, the shotpeened specimens exhibit high surface hardness and an enhancement in fatigue life. A notable impact of USSP on the fatigue crack initiation and growth of the alloy was also observed. The results show that the crack initiation at free-surface was suppressed due to the formation of a nanograined microstructure and fatigue crack initiation site shifts from surface to inside of the material. Further, the microstructural analysis proves that the nanograin formation and compressive stresses imparted by ultrasonic shot peening treatment are helpful in significant improvement of fatigue life.

scholarly journals Scanning Thermal Microscopy of Ultrathin Films: Numerical Studies Regarding Cantilever Displacement, Thermal Contact Areas, Heat Fluxes, and Heat Distribution

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 491
Author(s):  
Christoph Metzke ◽  
Fabian Kühnel ◽  
Jonas Weber ◽  
Günther Benstetter
Keyword(s):  
Thermal Properties ◽  
Ultrathin Films ◽  
Hexagonal Boron Nitride ◽  
Thermal Contact ◽  
Heat Transfer Process ◽  
Heat Propagation ◽  
Heat Fluxes ◽  
Detailed Knowledge ◽  
Scanning Thermal Microscopy ◽  
Thermal Microscopy

New micro- and nanoscale devices require electrically isolating materials with specific thermal properties. One option to characterize these thermal properties is the atomic force microscopy (AFM)-based scanning thermal microscopy (SThM) technique. It enables qualitative mapping of local thermal conductivities of ultrathin films. To fully understand and correctly interpret the results of practical SThM measurements, it is essential to have detailed knowledge about the heat transfer process between the probe and the sample. However, little can be found in the literature so far. Therefore, this work focuses on theoretical SThM studies of ultrathin films with anisotropic thermal properties such as hexagonal boron nitride (h-BN) and compares the results with a bulk silicon (Si) sample. Energy fluxes from the probe to the sample between 0.6 µW and 126.8 µW are found for different cases with a tip radius of approximately 300 nm. A present thermal interface resistance (TIR) between bulk Si and ultrathin h-BN on top can fully suppress a further heat penetration. The time until heat propagation within the sample is stationary is found to be below 1 µs, which may justify higher tip velocities in practical SThM investigations of up to 20 µms−1. It is also demonstrated that there is almost no influence of convection and radiation, whereas a possible TIR between probe and sample must be considered.

Enhanced corrosion resistance of the surface modified Ti-13Nb-13Zr alloy by ultrasonic shot peening

2021 ◽  
pp. 109597
Author(s):  
Pramod Kumar ◽  
G.S. Mahobia ◽  
Sumantra Mandal ◽  
V. Singh ◽  
Kausik Chattopadhyay
Keyword(s):  
Corrosion Resistance ◽  
Shot Peening ◽  
Ultrasonic Shot Peening ◽  
13Zr Alloy ◽  
Surface Modified

Adhesive penetration of wood cell walls investigated by scanning thermal microscopy (SThM)

Holzforschung ◽  
2008 ◽  
Vol 62 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Johannes Konnerth ◽  
David Harper ◽  
Seung-Hwan Lee ◽  
Timothy G. Rials ◽  
Wolfgang Gindl
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Surface Temperature ◽  
Cell Walls ◽  
Adhesive Contact ◽  
Wood Adhesive ◽  
Bond Line ◽  
Scanning Thermal Microscopy ◽  
Thermal Probe ◽  
Thermal Microscopy

Abstract Cross sections of wood adhesive bonds were studied by scanning thermal microscopy (SThM) with the aim of scrutinizing the distribution of adhesive in the bond line region. The distribution of thermal conductivity, as well as temperature in the bond line area, was measured on the surface by means of a nanofabricated thermal probe offering high spatial and thermal resolution. Both the thermal conductivity and the surface temperature measurements were found suitable to differentiate between materials in the bond region, i.e., adhesive, cell walls and embedding epoxy. Of the two SThM modes available, the surface temperature mode provided images with superior optical contrast. The results clearly demonstrate that the polyurethane adhesive did not cause changes of thermal properties in wood cell walls with adhesive contact. By contrast, cell walls adjacent to a phenol-resorcinol-formaldehyde adhesive showed distinctly changed thermal properties, which is attributed to the presence of adhesive in the wood cell wall.

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