Article
Engineering, Mechanical
Maria Hagarova, Pavel Peterka, Martin Mantic, Marek Vojtko, Gabriela Baranova, Milos Matvija
Summary: The fracture behavior of an electro-connector brass bolt with a strength of 360 MPa was studied using visual inspection, macroscopic and microscopic analysis, SEM (EDS) analysis, and microhardness measurement. The brass material had a structure of CuZn39Pb2 (CW612N) with two phasic alpha + beta' and the presence of coarse Pb particles. The analysis showed that loss of zinc due to dezincification was associated with stress corrosion cracking (SCC). The failure in alpha-phase regions was partial ductile, while the failure in beta-phase regions was mainly cleavage. The initiation of cracks may have occurred at the location of coarse Pb particles in the beta'-phase. The presence of minor secondary crack branching on the fracture surface indicated typical signs of SCC. Despite minimal prestressing in the bolted joint, the aforementioned factors synergistically activated the SCC mechanism.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Anirudh Udupa, Tatsuya Sugihara, Koushik Viswanathan, Ronald M. Latanision, Srinivasan Chandrasekar
Summary: This study reveals a unique surface stress-induced embrittlement effect in aluminum mediated by an adsorbed organic monolayer. Atomistic simulations and experimental results demonstrate the influence of carbon-chain length on surface stress, leading to a ductile-to-brittle transition and a significant reduction in deformation forces. The microscopic mechanism involves the suppression of dislocation emission at incipient crack tips.
Article
Engineering, Mechanical
Khurram Yaqoob, Fahim Hashmi, Waqas Hassan Tanveer
Summary: Due to its high ductility and formability, cartridge brass is widely used in various fields such as ammunition, plumbing, fasteners, and radiator cones. However, the brass shell used in a 130 mm shell was found to crack and suffer from dezincification during firing, leading to shell expansion and clogging. The failure analysis revealed that insufficient annealing time and dezincification were the main causes of crack initiation and propagation. The study recommended the use of dezincification-resistant alloys as starting materials and optimization of annealing time to improve the performance of brass shells.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Automation & Control Systems
Jakob Johansson, Volodymyr Bushlya, Charlotta Obitz, Rachid M'Saoubi, Joacim Hagstrom, Filip Lenrick
Summary: This study investigates the machining surface integrity, sub-surface deformation, and stress corrosion cracking resistance of two lead-free brass alloys. The results demonstrate that tool wear is the key factor influencing sub-surface deformation, with CuZn38As alloy exhibiting higher work-hardening and significant stress corrosion cracking.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Multidisciplinary
Chenyi Luo, Lorenzo Sanavia, Laura De Lorenzis
Summary: This paper focuses on fundamental modeling aspects of phase-field modeling for drying cracks in variably saturated porous media. Different formulations for total energy and variational analysis of damage evolution are evaluated. The analysis reveals the relationship between drying crack spacing and material and loading parameters.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Chengduo Wang, Pengzhan Ding, Fujie Ren, Qingkui Li, Jilin He, Benshuang Sun
Summary: The presence of oxygen in Mo10Nb alloy has a significant impact on its microstructure and hot deformation behavior. Oxygen atoms dissolve inside the grains of Mo10Nb, reducing the steady stress and increasing the diffusivity of the alloy at high temperature. This leads to transgranular embrittlement due to low cleavage energy and dislocation pile-up. Understanding the oxygen-induced embrittlement is crucial for the better design and performance of Mo10Nb alloy.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2023)
Article
Chemistry, Physical
Lenka Kuncicka, Michal Jambor, Adam Weiser, Jiri Dvorak
Summary: This study focuses on the detailed characterization of the structure and plastic flow of Cu-Zn-Pb brass fittings. The cracking was most likely induced by differences in chemical composition, with local changes in the crack location and an increase in microhardness contributing to local brittleness.
Article
Engineering, Mechanical
Emad Sharifi, Khalil Ranjbar
Summary: This article presents an analysis of the cause of failure for yellow brass tubes. Microscopic examinations and energy dispersive spectroscopic analyses revealed dezincification on the surface of the brass tubes, which initiated the cracks. The investigation concluded that the failure of the brass tubes was due to dezincification-assisted corrosion cracking, leading to leakage.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Materials Science, Multidisciplinary
Ronghui Li, Yishan Guan, Qinna Fan
Summary: The role of Bi in suppressing crack formation in electrodeposited brass films is investigated. Brass films grown from cyanide-free alkaline baths with Bi are found to be crack-free, while films grown without Bi contain several cracks. The stress measurements during film deposition show that compressive stresses are generated in Bi-co-deposited films, while tensile stresses are present in Bi-free films. The change in film stress from tensile to compressive is attributed to grain size coarsening and stacking fault formation in the Bi-co-deposited films. This study provides a pathway to growing crack-free brass films by controlling film stresses through Bi-co-deposition.
Article
Materials Science, Multidisciplinary
Sebastien Michel, Andras A. Sipos
Summary: This paper investigates the order of appearance and the position of meridional cracks in brittle domes using a dimension-reduced model. The results show that a simple, deterministic approach based on the Griffith theory of fracture predicts quasi-equidistant emerging cracks. The variation of the in-plane elastic support and the bending rigidity of the ring significantly affect the order of emergence. The relationship between the mechanical model and geometric properties of the emerging pattern is studied numerically.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Construction & Building Technology
Jun Xu, Xiaochun Xiao, Jiaxu Jin, Cunying Meng
Summary: The shape of defects can affect the initiation and occurrence of tensile cracks in brittle materials. Defects with sharp corners are more likely to induce the initiation and occurrence of tensile cracks, while defects with smooth edges require a larger area to breed tensile cracks. The defect shape also influences the strength and unstable toughness of the material.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Poonam Gupta, Suryanarayana Allu, Durga Prasad Karothu, Tamas Panda, Naba K. Nath
Summary: The shift in interest from crystal structure to mechanical property among crystal engineering researchers has led to a better understanding of molecular packing, intermolecular interactions, and mechanical behavior. It has been observed that certain molecular crystals exhibit both elastic and plastic flexibility, attributed to the presence of flexible pi interactions and slip systems, while benzamide crystals are found to be brittle materials. This highlights the impact of molecular packing and intermolecular interactions on the mechanical properties of solid crystalline materials under stress.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Engineering, Geological
Panyu Liao, Chengchao Guo, Fuming Wang, Wei Sun, Pengpeng Ni
Summary: In this study, the brittle damage of buried pipelines under different dip-slip faults was investigated using peridynamics. It was found that pipeline failure is more likely to occur within the zone of three times the pipe diameter from the fault plane, and reverse faulting is more harmful to the pipeline than normal faulting.
Article
Engineering, Biomedical
Abdelhafid Mallek, Abdelkader Miloudi, Mokhtar Khaldi, Mohammed-Mokhtar Bouziane, Belabbes Bachir Bouiadjra, Habiba Bougherara, Richie H. S. Gill
Summary: This study utilized Finite Element Modelling to analyze the behavior of temporary hip prostheses, and used Extended Finite Element Method to investigate the fracture behavior of reinforced spacers. The results showed that explicit finite element numerical modeling is an effective method to predict the mechanical behavior of spacers.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Article
Energy & Fuels
Jiahui Chen, Jie Feng, Fangqiang Wang, Qian Peng, Guitian Lan, Lihua Zhao, Longwen Wu
Summary: Cracking of conductive brass accessories in substations can result in overheating or an open circuit, causing serious impact on the safe and stable operation of the power grid system. This paper analyzed the cracking of a brass clamp that had been in service for seven years on the main transformer. The fracture morphology, chemical composition, and metallographic structure were systematically analyzed, and stress conditions were obtained through finite element simulation. The clamp exhibited transgranular brittle fracture with high oxygen content in the fracture, involving crack propagation along Pb particle connecting pathways, and stress concentration at the crack position. It was concluded that the failure was due to stress corrosion cracking and excessive content of Pb. Suggestions were proposed to prevent malfunction of the main transformer caused by clamp cracks.
