Investigation on High Temperature Mechanical Behaviors of TiC-γ′ Reinforced Ni Composite

Wenqiang Hu,Zhenying Huang,Qun Yu,Yuanbo Wang,Yidan Jiao,Yang Zhou,Hongxiang Zhai 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

A duplex TiC and γ′-Ni3(Al,Ti) reinforced nickel composite was fabricated through hot-press sintering a 30 vol% Ti2AlC–Nimixtures followed by thermal treatment method. Detailed microstructural detection was performed by adopting the routeof high-resolution transmission electron microscopy. In situ generated submicron TiC particulate and nanosized L12-γ′were homogeneously distributed in a fcc γ-Ni matrix. The high temperature tensile and compression behaviors of the TiC-γ′/Ni composites were evaluated in the temperature range of 25–800 °C. The results indicated that ultimate tensile andcompression properties exhibited the dependence of temperatures. The tensile properties of the composite determined at600 °C was 945 MPa, decreasing by 28.1% and 23.0% for elongation, compared to those of measured at room temperature(UTS = 1305 MPa, elongation = 5.35%). However, the yield strength exhibited the temperature independent until to 600 °C. The yield strength of the TiC-γ′/Ni composite are comparable with conventional superalloy under 600 °C, proving that TiCand γ′ particles constitute efficient reinforcements for Ni matrix according to thermal expansion dislocations strengthening,load-transfer and coherent strengthening mechanisms. The monotonic temperature dependence of yield strength at600–800 °C indicates that plastic deformation of TiC-γ′/Ni composite follows the thermally activated mechanism. TheTiC-γ′/Ni composite exhibited superior mechanical properties both at room and high temperatures, which can be ascribedto the synergistic strengthening effect in term of dislocation density, Orowan, coherent and atomic ordering strengtheningmechanisms. The present work reveals the deformation behaviors of in situ TiC-γ′/Ni composite from room to high temperatures,which is critical to predict the failure and thereby optimize the microstructure to further enhance the high temperatureproperties of TiC-γ′/Ni composite.

Thermal Shock Behavior of a Novel TiCx–Ni3(Al,Ti)/Ni Functionally Graded Composite

Qun Yu,Zhenying Huang,Guangming Zheng,Wenqiang Hu,Cong Lei,Yuanbo Wang,Yidan Jiao,Hongxiang Zhai 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

This paper focuses on the study of thermal shock behaviors of a novel TiCx–Ni3(Al,Ti)/Ni functionally graded material (FGM)fabricated from Ti3AlC2and Ni powders. Thermal shock resistance of resulted FGM was conducted by water quenching atdifferent temperatures, mechanical properties and microstructures after thermal shocks were correspondingly determined andcharacterized. The microstructure of the FGM after thermal shocks shows no cracks of instability failure between the transitionzones, and the reinforcement phases were closely combined with the matrix. Meanwhile, compared with the strengthof 1329 MPa without thermal shock, when the temperature of the thermal shock reached 800 °C and 1000 °C respectively,with 10 repeated heat-water quench cycles, the residual flexural strength of FGM decreased slightly, but it could still reach1100 MPa. Notably, the strength can still maintain at 843 MPa after 10 cycles of thermal shock at 1200 °C. Such excellentthermal shock performance may be the result of the good interfacial bonding and the special gradient structure, the oxidationlayer also plays a protective role.

Microstructural and Mechanical Properties of TiCX–Ni3(Al,Ti)/Ni Functionally Graded Composites Fabricated from Ti3AlC2 and Ni Powders

Guangming Zheng,Zhenying Huang,Qun Yu,Wenqiang Hu,Xingyang Qiu,A. Lixia,Yuanbo Wang,Yidan Jiao,Yang Zhou,Hongxiang Zhai 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.6

In this paper, a novel type of functionally graded material (FGM) was successfully fabricated from pure Ni and Ti3AlC2powder mixtures by hot-press sintering route at 1200 °C and 17 MPa. In each layer, Ti3AlC2particles transformed into TiCxphase, while the additional Al–Ti atoms decomposed from Ti3AlC2diffused into the Ni matrix, giving rise to the formationof γ′-Ni3(Al,Ti). Part of the submicron TiCxand Ni3(Al,Ti) particles were uniformly distributed in the Ni matrix, whilesome of the TiCxmaintained the original Ti3AlC2plate-like morphology. Both TiCxand Ni3(Al,Ti) content decreased from60Ti3AlC2/Ni layer to 10Ti3AlC2/Ni layer in a stepwise manner was fabricated. The microstructural analysis indicatesthat no cracks, delamination and step-type abrupt changes occured in the graded layer of the manufactured FGM. Flexuralstrength and Vickers hardness enhanced with the increasing Ti3AlC2content except for fracture strain and toughness. Theoverall fracture toughness and the flexural strength of FGM can reach 21.76 MPa m1/2 and 1329 ± 34 MPa, respectively. Theprepared FGM, herein, with a hard ceramic surface on one side to resist local plastic deformation, and a ductile metallicsurface on the other side to provide toughness.

Adaptive Backstepping Sliding Mode Control of Tractor-trailer System with Input Delay Based on RBF Neural Network

Zengke Jin,Zhenying Liang,Xi Wang,Mingwen Zheng 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.1

In this paper, an adaptive sliding mode neural network(NN) control method is investigated for input delaytractor-trailer system with two degrees of freedom. An uncertain camera-object kinematic tracking error model of atractor car with n trailers with input delay is proposed. Radial basis function neural networks(RBFNNs) are appliedto approximate the unknown functions in the error model. A sliding mode surface with variable structure controlis designed by using backstepping method. Then, an adaptive NN sliding mode control method is thus obtained bycombining Lyapunov-Krasovskii functionals. The controller realizes the global asymptotic trajectories tracking ofthe kinematics system. The stability of the closed-loop system is strictly proved by the Lyapunov theory. Matlabsimulation results demonstrate the feasibility of the proposed method.

Preparation of environmentally friendly low‐cost mullite porous Ceramics and the effect of Waste Glass Powder on structure and mechanical Properties

Wei Lian,Yan Liu,Wenjie Wang,Yangtao Dong,Sheng Wang,Zhenying Liu,Yin Liu 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2

Environmentally friendly low-cost porous ceramics are prepared with 98.2 wt% mining waste as the raw materials at 1180 °C. The glass powder forms liquid phase at high temperatures, promoting the densification of the materials. X-ray diffraction (XRD) results show that the formation of mullite is affected by sintering temperature and content of liquid phase. The enhancement in densification is verified by the scanning electron microscopy (SEM) analysis results. According to the evolution of pore structure, the effect of the glass powder on the structure is confirmed. The number ratio of pores of < 8 μm to those of 8 ~ 20 μm is varied from 7:2 to 2:7. The minimum apparent porosity is 31.22 %, while the maximum density and linear shrinkage are 1.75 g/cm 3 and 8.48 %, respectively. The flexural strength (three-point bending method) was increased from 7.47 MPa to 28.36 MPa, indicating that the addition of glass powder could increase mechanical properties of the porous ceramics. Therefore, solid wastes can be used as the resource to develop porous mullite ceramics.

Artificial diet development for mass rearing and its effect on the reproduction of yellow peach moth, Conogethes punctiferalis (Guenée)

Jing Dapeng,Zhang Tiantao,Bai Shuxiong,He Kanglai,Prabu Sivaprasath,Wang Zhenying 한국곤충학회 2021 Entomological Research Vol.51 No.3

Yellow peach moth, Conogethes punctiferalis(Guenée) (Lepidoptera: Crambidae), is a very destructive fruit borer in Eastern Asia and Australia. A successful artificial diet and rearing protocol are urgently needed for its biological control and research. In this study, we developed and assessed four artificial diets: AD-1, AD-2, AD-3 and AD-4, for rearing yellow peach moth larvae. AD-1 is effective supplements, leading to the larval survival rate of 82.05%, percentage of pupation 79.48%, mean pupa weight of 76.53 mg, emergence rate of 95.25%, and an adult fecundity rate of 121 eggs/female. Using it to feed can shorten the whole generation developmental period to 33 days. Based on this diet AD-1, we also develop a suitable mass rearing method. During the larval stages providing three- to four-time fresh diet can keep a healthy larval colony.

Molecular identification and functional analysis of Niemann-Pick type C2 protein in Macrocentrus cingulum Brischke (Hymenoptera: Braconidae)

Lin Maung Kyaw,Jing Dapeng,Zhang Tiantao,Prabu Sivaprasath,He Kanglai,Bai Shuxiong,Wang Zhenying 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Niemann-Pick type C2 (NPC2) proteins in arthropods have been extensively differentiated and possibly dupli cated according to environmental conditions and are probable to have different functions. The participation of NPC2 proteins in chemical communication in arthropods brings new objectives in environmental-friendly stra tegies for pest population control. In this study, NPC2 gene in Macrocentrus cingulum (McinNPC2) was newly identified by rapid amplification cDNA ends (RACE) technology. McinNPC2 amino acid sequence alignment with other representative NPC2 annotates to evaluate the highly conserved consensus amino acids, but with odorant binding proteins in M. cingulum show that only one consensus amino acid. Primary six-cysteine structures that are same to odorant binding proteins in M. cingulum were observed in McinNPC2. Phylogenetic analysis of McinNPC2 indicated that the nearest monophyletic group forming one clade with high posterior probability values clusters as Cyphomyrmex costatus (CcosNPC2) whereas the nearest evolutionary relation group as some odorant binding proteins. Moreover, quantitative real-time PCR (qPCR) measurements show that the McinNPC2 gene expression level in various tissues of the female is significantly and ubiquitously higher than in male, whereas the highest expression level in female antennae. We further explore the binding characterization of recombinant McinNPC2 to candidate odor molecules and did the modeling and docking simulations. The results showed ligands binding specificity and docking tests results indicate that β-ionone, an aroma compound commonly found in essential oils, can strongly bind with McinNPC2. In conclusion, we proposed that McinNPC2 may be involved in chemical communication and play roles in perception of plant volatiles.