• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.427-430
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• 2008

The influence of subsequent annealing treatment on the dynamic deformation and the fracture behavior of submicrocrystalline Al-4.4%Mg alloy is investigated in this study. After inducing an effective strain of 8 via equal-channel angular pressing at $200^{\circ}C$, most of the grains are considerably reduced to nearly equiaxed grains of $0.3{\mu}m$ in size. With an increment of various subsequent heat treatments for 1 hour, resultant microstructures are found to be fairly stable at temperatures up to $200^{\circ}C$, suggesting that static recovery will be dominantly operative, whereas grain growth is pronounced above $250^{\circ}C$. The results of tensile tests show that yield and ultimate tensile strength decrease, but elongation-to-failure and strain hardening rate increase with an increase in annealing temperatures. The dynamic deformation and the fracture behavior retrieved with a series of torsional tests are explored with respect to annealed microstructures. Such mechanical response is analyzed in relation to resultant microstructure and fracture mode.

• Korean Journal of Metals and Materials
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• v.49 no.11
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• pp.910-915
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• 2011

The microstructures and mechanical properties of roll-bonded STS439/Al1050/STS304 clad materials were investigated after an annealing process at various temperatures. Interfacial layer was developed at the STS439/Al1050 and Al1050/STS304 interfaces at $550^{\circ}C$. STS439/Al1050/STS304 clad metals fractured suddenly in a single step and the fracture decreased with increasing annealing temperatures at $450^{\circ}C$. After annealing at $550^{\circ}C$, samples fractured in three steps with each layer fracturing independently. Interfacial layers formed at $550^{\circ}C$ with a high Vickers microhardness were found to be brittle. During tensile testing, periodic parallel cracks were observed at the interfacial reaction layer. Observed micro-void between Al1050 and the interfacial layer was found to weaken the Al1050/reaction layer interface, leading to the total separation between Al1050 and the reaction layer.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.530-535
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• 1999

In recently, annealing process of cold rolled sheet tend to change to continuous annealing process for improving quality, saving yield. In the meantime as demand for various kind and small lot of products has been increasing, batch annealing has been appreciated for its small restriction for the operation. So, we tested on the effect for the proper heating temperatures, heating time of cycle, cooling time and total cycle time in this annealing process of hi tensile strength steel for automobile. As a result of several investigation. we confirmed for the following characteristics; In this process, we knew that 68$0^{\circ}C$ is suitable for this heating temp. cycle heating time of 38 Hr, cooling time of 31 Hr and total cycle time of 70 Hr. Still more, we could know that it is proper for cold rolling before annealing to be managed by 7 pass because of the act on high pressure.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.4
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• pp.199-202
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• 2011

Ga doped ZnO thin films were deposited with RF magnetron sputtering on glass substrate without intentional substrate heating and then the effect of post deposition annealing temperature on the structural, optical and electrical properties of the films was investigated. The post deposition annealing process was conducted for 30 minutes in a vacuum of $1{\times}10^{-3}$ Torr and the vacuum annealing temperatures were 150 and $300^{\circ}C$, respectively. As increase annealing temperature, GZO films show the increment of the prefer orientation of ZnO (002) diffraction peak in the XRD pattern and the optical transmittance in a visible wave region was also increased, while the electrical sheet resistance was decreased. The figure of merit obtained in this study means that GZO films which vacuum annealed at $300^{\circ}C$ have the highest optoelectrical performance in this study.

• Journal of Powder Materials
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• v.13 no.1 s.54
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• pp.25-32
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• 2006

The alumina dispersion-strengthened (DS) C15715 Cu alloy fabricated by a powder metallurgy route was annealed at temperatures ranging from $800^{\circ}C\;to\;1000^{\circ}C$ in the air and in vacuum. The effect of the annealing on microstructural stability and room-temperature mechanical properties of the alloy was investigated. The microstructure of the cold rolled OS alloy remained stable until the annealing at $900^{\circ}C$ in the air and in vacuum. No recrystallization of original grains occurred, but the dislocation density decreased and newly formed subgrains were observed. The alloy annealed at $1000^{\circ}C$ in the air experienced recrystallization and grain growth took place, however annealing in vacuum at $1000^{\circ}C$ did not cause the microstructural change. The mechanical property of the alloy was changed slightly with the annealing if the microstructure remained stable. However, the strength of the specimen that was recrystallized decreased drastically.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.306-309
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• 2019

Titanium (Ti) doped indium oxide (In₂O₃) films were deposited on glass substrates by RF magnetron sputtering and the films were rapid thermal annealed at 100, 200, and 300℃, respectively to investigate the influence of the rapid annealing on the opto-electrical performance of the films. The grain size of In₂O₃ (222) plane increased with annealing temperatures and their electrical resistivity decreased to as low as 8.86×10^-4 Ωcm at 300℃. The visible transmittance also improved from 77.1 to 79.5% when the annealing temperature increased. The optical band gap of the TIO films shifted from 4.010 to 4.087 eV with increases in annealing temperature from room temperature to 300℃. The figure of merit shows that the TIO films annealed at 300℃ had better optical and electrical performance than the other films prepared using lower-temperature or no annealing.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.149-152
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• 2004

In this paper, we present the film bulk acoustic resonator (FBAR) devices fabricated by considering the effects of annealing temperature on zinc oxide (ZnO) film growth characteristics. In order to determine the annealing temperature and annealing time at which the ZnO film can have good material properties, the several resonators containing ZnO layers were fabricated and annealed at various temperatures from $27^{\circ}C\;to\;300^{\circ}C$ in Ar gas ambient. The effects of the annealing temperature and annealing time on the ZnO film properties were comprehensively studied in order to further improve the resonance characteristics of FBAR resonators.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.16-19
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• 2004

In this paper, we present the film bulk acoustic resonator (FBAR) devices fabricated by considering the effects of annealing temperature on zinc oxide (ZnO) film growth characteristics. In order to determine the annealing temperature and annealing time at which the ZnO film can have good material properties, the several resonators containing ZnO layers were fabricated and annealed at various temperatures from 27$^{\circ}C$ to 30$0^{\circ}C$ in Ar gas ambient. The effects of the annealing temperature and annealing time on the ZnO film properties were comprehensively studied in order to further improve the resonance characteristics of FBAR resonators.

• Korean Journal of Materials Research
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• v.12 no.10
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• pp.820-824
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• 2002

It is of importance to know that the bonding strength and interfacial stress of SOI wafer pairs to meet with mechanical and thermal stresses during process. We fabricated Si/2000$\AA$-SiO$_2$ ∥ 2000$\AA$-SiO$_2$/Si SOI wafer pairs with electric furnace annealing, rapid thermal annealing (RTA), and fast linear annealing (FLA), respectively, by varying the annealing temperatures at a given annealing process. Bonding strength and interfacial stress were measured by a razor blade crack opening method and a laser curvature characterization method, respectively. All the annealing process induced the tensile thermal stresses. Electrical furnace annealing achieved the maximum bonding strength at $1000^{\circ}C$-2 hr anneal, while it produced constant thermal tensile stress by $1000^{\circ}C$. RTA showed very small bonding strength due to premating failure during annealing. FLA showed enough bonding strength at $500^{\circ}C$, however large thermal tensile stress were induced. We confirmed that premated wafer pairs should have appropriate compressive interfacial stress to compensate the thermal tensile stress during a given annealing process.

• Journal of the Korean Society for Heat Treatment
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• v.21 no.6
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• pp.307-313
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• 2008

The tensile deformation and shape recovery behaviors were studied in Ni-Ti shape memory wires showing different transformation characteristics by annealing at $200{\sim}600^{\circ}C$. Both R phase ${\rightarrow}$ B19' martensitic transformation at lower temperature and B2 ${\rightarrow}$ R phase transformation at higher temperature occurred in the shape memory wires annealed at $200{\sim}500^{\circ}C$. Transformation temperature and heat flow of B19' martensite increase but those of R phase main almost constant even with increasing annealing temperature. In the case of wires annealed and then cooled to $20^{\circ}C$, plateau on stress-strain curves in tensile testing can be observed due to the collapse of R phase variants and the formation of deformation-induced B19' martensite. In the case of wires annealed and then cooled to $-196^{\circ}C$, however, plateau on stress-strain curves does not appear and stress increases steadily with increasing tensile deformation. Comparing shape recovery rate with cooling temperature after annealing, shape recovery rate of the wire cooled to $20^{\circ}C$ is higher than that of the wire cooled to $-196^{\circ}C$ after annealing, and maximum shape recovery rate of 95% appears in the wire annealed at $400^{\circ}C$ and then cooled to $20^{\circ}C$. $R_s$ and $R_f$ temperatures measured during shape recovery tests are higher than $A_s$ and $A_f$ temperatures measured by DSC tests even at the same annealing temperature.