Failure Mechanisms of Graded Ceramic Tool in Ultra High Speed Dry Milling of Inconel 718

Guangming Zheng,Jun Zhao,Anhai Li,Xiaobin Cui,Yonghui Zhou 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

A graded ceramic tool material was fabricated by hot-pressing. Its cutting performance and failure mechanisms were investigated in dry face milling of Inconel 718 using round inserts at ultra high speeds ranging from 500 to 1600 m/min. The results showed that the microscopic chip shape was serrated type and the minimal cutting force was obtained at 900 m/min under this ultra high speed cutting conditions. Due to the enhanced mechanical properties and higher fracture resistance, the graded tool showed a selfsharpening characteristic. And the notch wear resistance of the graded tool was higher than that of the common reference tool under the same cutting condition. The failure mechanisms involved chipping, flaking, abrasive wear and adhesive wear. The mechanisms responsible for the higher cutting performance of the graded tool were determined to be the higher mechanical properties. The understanding of the failure mechanisms in ultra high speed milling processes can provide the guidance for the proper application of the tools, furthermore the guidance for tool materials design.

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.

Incorporating Bidirectional Heuristic Search and Improved ACO in Route Planning

Guangming Xiong,Xiaoyun Li,Shuai Zhou,Hao Lu,Yan Jiang,Jianwei Gong 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.7

A multi-objective multi-node dynamic route planning system for a vehicle is presented in this paper. In this system, a bidirectional heuristic search algorithm is designed to perform path planning between two nodes in a topological map created by OpenStreetMap for urban scenarios. And then an improved multi-objective Ant Colony Optimization (ACO) algorithm considering the timeliness of goal nodes is proposed to generate the node sequence. Experimental results validated the proposed approach.

Short-Term Response of Bacterial Populations in Compost-Amended Soil to Additions of Biochar

Miaomiao He,Guangming Tian,Gendi Zhou 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Machine Learning Complex Interactions Among Recovery, Precipitation, and Recrystallization for Nb Micro-Alloyed Steels

Xin Li,Qiming Jiang,Xiaoguang Zhou,Guangming Cao,Guodong Wang,Zhenyu Liu 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.1

Static softening behaviors that mainly includes recovery and recrystallization play the important role in controlling themicrostructure and mechanical properties of micro-alloyed steels during hot rolling, which is the essence for optimizing thecontrolled rolling processes. Chemical compositions and deformation conditions are the key factors to the static softeningbehaviors, but their quantitative influences are not clear due to the complex interactions among softening, precipitation, andhot deformation. In the present work, an integrated machine learning (ML) system for the static softening behaviors underdifferent chemical compositions and deformation conditions is established, based on ML modeling of strain-induced precipitationand the data collected from the published literatures. The particle swarm optimization (PSO) algorithm was usedto determine the recovery and recrystallization model parameters for different niobium (Nb) micro-alloyed steels. Supportvector machine (SVM) was used to establish the relationships between these parameters and compositions and processingparameters. By using the integrated ML system, the effects of compositions and deformation conditions on the static softeningcritical temperature (SSCT), static softening behavior were predicted. The predictions were compared with the measuredvalues, indicating that the ML system can accurately predict static softening behaviors for different steel grades under differentprocessing conditions, which lays a foundation for the accurate design of controlled rolling processes.

A bi-directional valveless piezoelectric micropump based on the Coanda effect

Zheng Zhang,Lipeng He,Jianwen Zhou,Dianbin Hu,Yi Hou,Guangming Cheng 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.2

In this paper, the hydrodynamic characteristics of a piezoelectric micropump operate on the Coanda effect, and the mechanism of bi-directional pumping are analyzed by numerical simulation and experiments. The research focuses on the different positions of the fluid deflector and the influence on the output of the micropump. The results show that a closer fluid deflector to the inlet can produce greater vortices in the suction process due to the Coanda effect, and the backflow diminishing is more significant as well. Moreover, the different positions of the fluid deflector can cause a phenomenon that the micropump will achieve bi-directional pumping. As a finding, vortices arranged in pairs could improve the rectification efficiency of the micropump. The micropump achieves a maximum flow rate of 40.5 ml/min and back pressure of 5.76 cmH 2 o. In addition, the maximum flow rate per unit area can reach 305.2 μl/(min mm 2 ).

A New Interfacial Model for Transverse Mechanical Properties of Unidirectional Fiber Reinforced Composites

Deng’an Cai,Xiaopei Wang,Yaohui Shi,Xufeng Hao,Yuan Qian,Guangming Zhou 한국섬유공학회 2021 Fibers and polymers Vol.22 No.2

Transverse mechanical properties play an important role in the study of fiber reinforced composite materials. Anexperimental and numerical study on mechanical properties and damage behavior of unidirectional fiber reinforcedcomposites under transverse load is presented. The quasi-static tensile and compressive tests were carried out to obtainmechanical properties of unidirectional fiber reinforced composites under transverse tension and compression. The fracturemorphologies of the specimens were observed by scanning electron microscopy (SEM) to reveal their distinct damagemechanism. Considering the effects of interface, a new interfacial model is proposed. Two representative volume elements(RVEs) of basic and interfacial models are established for comparison analysis. The predicted results agree well with theexperimental data. The introduction of interfacial layer has little effect on the prediction of transverse modulus, but canimprove the accuracy of the predicted transverse strength. The fiber volume fraction has a great influence on the transversemechanical properties of unidirectional fiber reinforced composites. As the fiber volume fraction increases, its transversemodulus increases, but both the transverse strength and the ultimate strain decrease.

Effect of Loop Yarns on Mechanical Properties of Carbon Fibre/Epoxy Composites

Mingyang Shao,Deng’an Cai,Nan Zhang,Qihang Yu,Fangtian Hu,Ning Kuang,Guangming Zhou 한국섬유공학회 2023 Fibers and polymers Vol.24 No.10

The general two-dimensional (2D) woven laminated composite (GWLC) is widely used in aviation, aerospace and high speed railways, and its superior specific stiffness and strength substantially reduce the weight of the structural components. However, when the GWLC is damaged by flexural, shear and impact loads, the layers are prone to delamination. To improve the interlayer properties of the GWLC, a loop warp yarn is added to the plain fabric by means of three-dimensional (3D) weaving technology, resulting in a double-side-loop fabric with Z-directional fibers. This paper investigates the double-notched shear (DNS) properties, in-plane shear properties, and flexural properties of GWLC and a new double-side-loop 2D woven laminated composite (DWLC). The test results verify that adding the loop warp yarns can greatly improve the interlayer properties of the general 2D woven laminated composites. The DWLC increases the interlaminar shear strength by 81.5%, the in-plane shear strength by 49.4%, and the flexural strength and modulus by 90.2% and 61.4%, respectively. The excellent mechanical properties of the DWLC lay a foundation for loop fabrics in engineering applications.