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Amanov, A.,Umarov, R. Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.441 No.-
<P><B>Abstract</B></P> <P>In this study, a combination of local heat treatment (LHT) with (w/) and without (w/o) ultrasonic nanocrystal surface modification (UNSM) technique was applied to Inconel 690 alloy at room and high temperatures (RT and HT). The main purpose of this study is to investigate the influence of LHT w/ and w/o UNSM processing on the mechanical and fretting wear mitigation of Inconel 690 alloy. The surface roughness of the specimens was increased with increasing the LHT temperature w/ and w/o UNSM from RT to HT at 700 °C, while the surface hardness of the RT and HT at 300 °C specimens was increased and softening occurred at HT at 700 °C. The mechanical properties of the specimens were investigated using a tensile stress test. It was found that the stress-strain curve of the UNSM-treated at RT exhibited better mechanical characteristics in comparison with the as-received one. Moreover, the specimens treated at HT at 300 and 700 °C exhibited better results in terms of strain, but there was no significant difference in stress. The UNSM treated specimens at HT of 300 °C had better results in comparison with other specimens. In addition, the fretting wear resistance of those specimens was assessed using a ball-on-disk fretting wear tester at temperatures of 25 and 80 °C. The fretting wear resistance of Inconel 690 alloy was also increased by the combination of LHT + UNSM processing, which may be attributed to the increase in mechanical properties, increase in surface roughness, induced compressive residual stress and the presence of a nanostructured surface layer. Hence, Inconel 690 alloy with the increased mechanical properties and fretting wear resistance by the combination of LHT + UNSM processing could be beneficial for nuclear applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A local heat treatment along with UNSM treatment was employed to Inconel 690 alloy. </LI> <LI> The surface roughness was increased with increasing the temperature. </LI> <LI> The surface hardness was reduced at 700 °C, while it was increase at 300 °C. </LI> <LI> The fretting wear was mitigated by local heat treatment along with UNSM treatment. </LI> <LI> The role of local heat treatment and UNSM processing is significant. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Amanov, A.,Sasaki, S.,Cho, I.S.,Suzuki, Y.,Kim, H.J.,Kim, D.E. Scientific and Technical Press ; Elsevier Science 2013 Materials & design Vol.47 No.-
In this work, the friction and wear behavior of Fe-Ni-Cr alloy specimens processed by direct metal laser sintering (DMLS) method was investigated by using a ball-on-disk reciprocating tribotester sliding against a hardened steel ball under dry sliding conditions. After DMLS, the specimens were further treated by hot isostatic pressing (HIP) in order to reduce the porosity and to increase the density. Subsequently, one of the specimens was subjected to high-frequency ultrasonic peening (HFUP) with the aim to enhance the tribological properties. The microstructural characterization was conducted using a scanning electron microscope (SEM) and an atomic force microscope (AFM). In addition, nano-scratch tests were carried out on the specimens using a nano-scratch testing (NST) system. The friction and nano-scratch tests results showed that the HFUP-treated specimen led to a reduction in friction coefficient and wear rate, and an increase in resistance to scratch compared to that of the HFUP-free specimen, which may be attributed to the increase in hardness and the formation of corrugated structure.
J.P.B.A Sembiring,Seimi Choi,Choongho Sanseong,Junsuek Ro,A. Amanov,Y.S. Pyun 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.5
The existing ultrasonic assisted grinding used for machining hard and brittle material still has some drawbacks, such as low material removal rate rapid tool wear and low quality of surface finish. To resolve those problem, a retrofit idea of existing concept is propose. In this paper, an idea to retrofit the existing ultrasonic assisted grinding machining center is proposed by changing the spindle design, tool tip and the modification of ultrasonic transducer. The consideration behind design changing and modification of existing concept will be discussed. Due to the design changing and modification, the capability of high speed rotational machining and the elliptical tool motion of 2D Vibration Assisted Machining (VAM) are expected to be obtained. Due to the elliptical tool motion, it is expected that the cutting force can be reduced, extension of tool life, capability to cut the brittle material in ductile regime and improvement surface finish can be obtained.