scholarly journals Microstructural Modeling and Strengthening Mechanism of TiB/Ti-6Al-4V Discontinuously-Reinforced Titanium Matrix Composite

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 827 ◽  
Author(s):  
Shuai Zhao ◽  
Yangjian Xu ◽  
Changliang Pan ◽  
Lihua Liang ◽  
Xiaogui Wang
Keyword(s):  
Finite Element ◽  
Matrix Composite ◽  
Distribution Density ◽  
Volume Fraction ◽  
Element Model ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Finite Element Software ◽  
Multiple User ◽  
Thiessen Polygon

A novel modeling method was proposed to provide an improved representation of the actual microstructure of TiB/Ti-6Al-4V discontinuously-reinforced titanium matrix composite (DRTMC). Based on the Thiessen polygon structure, the representative volume element (RVE) containing the complex microstructures of the DRTMC was first generated. Thereafter, by using multiple user-defined subroutines in the commercial finite element software ABAQUS, the application of asymmetric mesh periodic boundary conditions on the RVE was realized, and the equivalent elastic modulus of the DRTMC was determined according to the homogenization method. Through error analyses on the experimental and calculated results regarding the equivalent elastic parameters of the DRTMC, the rationality of generating the DRTMC finite element model by using the present method was validated. Finally, simulations based on four types of network-like models revealed that the present simplifications to the particle shape of the reinforcement phase had less of an influence on the overall composite strength. Moreover, the present study demonstrates that the DRTMC enhancement is mainly attributed to the matrix strengthening, rather than the load-transferring mechanism. The strengthening influences of the distribution forms of the reinforcement phases, including their distribution density and orientation, were studied further. It was found that both the higher distribution density and limited distribution orientation of the particles would increase the probability of overlapping and merging between particles, and; therefore, higher strength could be yielded when the volume fraction of the reinforcement phase reached a certain threshold. Owing to the versatility of the developed methods and programs, this work can provide a useful reference for the characterization of the mechanical properties of other composites types.

scholarly journals Effect of Graphene Nanosheets Content on Microstructure and Mechanical Properties of Titanium Matrix Composite Produced by Cold Pressing and Sintering

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1024 ◽  
Author(s):  
Milad Haghighi ◽  
Mohammad Shaeri ◽  
Arman Sedghi ◽  
Faramarz Djavanroodi
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Volume Fraction ◽  
Graphene Nanosheets ◽  
Microstructural Analysis ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Cold Pressing ◽  
Sintering Time ◽  
Microstructure And Mechanical Properties

The effect of graphene nanosheet (GNS) reinforcement on the microstructure and mechanical properties of the titanium matrix composite has been discussed. For this purpose, composites with various GNS contents were prepared by cold pressing and sintering at various time periods. Density calculation by Archimedes’ principle revealed that Ti/GNSs composites with reasonable high density (more than 99.5% of theoretical density) were produced after sintering for 5 h. Microstructural analysis by X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM) showed that TiC particles were formed in the matrix during the sintering process as a result of a titanium reaction with carbon. Higher GNS content as well as sintering time resulted in an increase in TiC particle size and volume fraction. Microhardness and shear punch tests demonstrated considerable improvement of the specimens’ mechanical properties with the increment of sintering time and GNS content up to 1 wt. %. The microhardness and shear strength of 1 wt. % GNS composites were enhanced from 316 HV and 610 MPa to 613 HV and 754 MPa, respectively, when composites sintered for 5 h. It is worth mentioning that the formation of the agglomerates of unreacted GNSs in 1.5 wt. % GNS composites resulted in a dramatic decrease in mechanical properties.

scholarly journals Characteristics of powder metallurgy pure titanium matrix composite reinforced with multi-wall carbon nanotubes

2009 ◽  
Vol 69 (7-8) ◽  
pp. 1077-1081 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Hisashi Imai ◽  
Junko Umeda ◽  
Bunshi Fugetsu
Keyword(s):  
Carbon Nanotubes ◽  
Powder Metallurgy ◽  
Matrix Composite ◽  
Pure Titanium ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Multi Wall Carbon Nanotubes

A pragmatic approach for the evaluation of depth-sensing indentation in the self-similar regime

2021 ◽  
pp. 1-24
Author(s):  
Hamidreza Mahdavi ◽  
Konstantinos Poulios ◽  
Christian F. Niordson
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Depth Sensing ◽  
Finite Element Software ◽  
Element Simulation ◽  
Unique Material ◽  
Reverse Analysis ◽  
Supplementary Material ◽  
Two Parameters ◽  
Force Displacement

Abstract This work evaluates and revisits elements from the depth-sensing indentation literature by means of carefully chosen practical indentation cases, simulated numerically and compared to experiments. The aim is to close a series of debated subjects, which constitute major sources of inaccuracies in the evaluation of depth-sensing indentation data in practice. Firstly, own examples and references from the literature are presented in order to demonstrate how crucial self-similarity detection and blunting distance compensation are, for establishing a rigorous link between experiments and simple sharp-indenter models. Moreover, it is demonstrated, once again, in terms of clear and practical examples, that no more than two parameters are necessary to achieve an excellent match between a sharp indenter finite element simulation and experimental force-displacement data. The clear conclusion is that reverse analysis methods promising to deliver a set of three unique material parameters from depth-sensing indentation cannot be reliable. Lastly, in light of the broad availability of modern finite element software, we also suggest to avoid the rigid indenter approximation, as it is shown to lead to unnecessary inaccuracies. All conclusions from the critical literature review performed lead to a new semi-analytical reverse analysis method, based on available dimensionless functions from the literature and a calibration against case specific finite element simulations. Implementations of the finite element model employed are released as supplementary material, for two major finite element software packages.

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