scholarly journals Setting of Natural Fracture Splitting Surface on Connecting Rod and Its Formation Mechanism

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 590
Author(s):  
Fengjun Zhang ◽  
Yi Zhang
Keyword(s):  
Melting Point ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Formation Mechanism ◽  
Surface Deformation ◽  
Material Selection ◽  
Interface Reaction ◽  
Natural Fracture ◽  
Fracture Splitting ◽  
Splitting Process

To break through the limitation of fracture splitting process on material selection and solve problems during fracture splitting such as parts tearing, failing to split, dropping dregs, fracture surface deformation and so on, a new technique of setting natural splitting surface in casting blank is proposed, aiming to achieve brittle fracture along pre-set surface during fracture splitting process. In this research, casting blanks are produced with metal molds. A layer of AZ31 foil is set in advance before casting, the layer interacts with liquid LD10 aluminum alloy, forming a brittle interface layer across the whole casting, then a fracture splitting hole is machined in the middle of the casting blank and cracking grooves are machined on the inner hole near the interface to achieve fracture splitting. Experiment revealed that the initial crack on the specimen starts from the root of the cracking groove, and the crack basically expands along the pre-set fracture splitting surface. The fracture surface is characterized by flaky brittle fracture. There is residual magnesium and pellumina, which have characteristics of melt with low-melting point, and micro-porosity in the fracture. Further analysis suggests that the formation mechanism of a natural fracture splitting surface can be described as follows: the magnesium foil with strong oxidation in high-temperature alloy liquid interacts with the pellumina at the front of liquid flow, which forms a interface. Meanwhile a layer of melt with a low-melting point forming as a result of interface reaction is pushed to the edge of the grain boundary, and surface liquid film shrinks to be micro-porosity. With such a combined effect it finally forms the brittle surface, which provides the condition for conducting subsequent fracture splitting process.

Analysis of the Crack Fracture Morphology of the Asphalt Mixture under Tensile Stress Effects

2011 ◽  
Vol 250-253 ◽  
pp. 3533-3537 ◽  
Author(s):  
Li Hua Zhao ◽  
Jing Yun Chen ◽  
Sheng Wu Wang
Keyword(s):  
Brittle Fracture ◽  
Fracture Surface ◽  
Tensile Stress ◽  
Mechanical Characteristics ◽  
Asphalt Mixture ◽  
Fracture Morphology ◽  
Microscopic Mechanism ◽  
Interface Zone ◽  
Stress Effects ◽  
Bending Fracture

Through studying the bending fracture and cleavage fracture of the asphalt mixture within the different temperature condition, confirming that the temperature influences the microscopic mechanism of mixture cracking: the fracture is relatively flat with low temperture, the destruction of the asphalt mixture is also mainly result of the brittle fracture; As the temperature rise, fracture surface becomes coarse, some part show large plastic elapse deformation. Adding fiber can reduce thickness of the asphalt membrane, improve the bonding strength of asphalt mastic, and greatly increase the ratio of the aggregate fracture and interface zone fracture, so as to enhance the asphalt mixture crack-resistance. The fracture morphology of asphalt mixture has a better reflection for its mechanical characteristics.

Anisotropic Mechanical Properties of Rapid Prototyping Parts Fabricated by Stereolithography

2021 ◽  
Vol 13 (9) ◽  
pp. 1812-1819
Author(s):  
Na-Na Yang ◽  
Hao-Rui Liu ◽  
Ning Mi ◽  
Qi Zhou ◽  
Li-Qun He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Elongation At Break ◽  
Build Orientation ◽  
Range Distribution ◽  
Anisotropic Mechanical Properties ◽  
Orientation Experiment

Stereolithography (SLA)-manufactured parts behave with anisotropic properties due to the varying interface orientations generated by the layer-based manufacturing process. Part build orientation is a very important factor of anisotropic mechanical properties. In this paper, the build orientation experiment was designed to study the anisotropic behaviour of the mechanical properties of the SLA parts based on the orientation relationship between the force and the layer. The results show that there are obvious brittle characteristics on the fracture surface of the specimens and microcracks perpendicular to the direction of the layer distributed on the side of the fracture. The mechanical properties under brittle fracture have different degrees of sensitivity to the build orientation. Among all the build orientations, whether a specimen is built flat or on an edge shows obvious difference in tensile strength, and the relative range distribution reaches 35%. The changes in elastic modulus and the elongation at break are the most obvious in different angles relative to the XY plane, and the relative range distribution reaches 62% and 56% respectively. In all the build orientations designed, the tensile strength is the largest when it is placed on the edge at 0° with Y-axis in the XY plane, the elastic modulus is the largest when it was placed vertically, and the elongation at break is the largest when it is placed flat at 45° with Y-axis in the XY plane.

Fracture Behavior of an AlMgMnSc Alloy at Different Temperatures

2021 ◽  
Vol 1016 ◽  
pp. 292-296
Author(s):  
Yuliya Igorevna Borisova ◽  
Diana Yuzbekova ◽  
Anna Mogucheva
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Fine Grained ◽  
Angular Pressing ◽  
Different Temperatures ◽  
Elongation To Failure

An Al-4.57Mg-0.35Mn-0.2Sc-0.09Zr (wt. %) alloy was studied in the fine-grained state obtaining after equal channel angular pressing. The mechanical behavior of alloy at the temperatures 173 K, 298 K and 348 K and at strain rate 1×10–3 s–1 is studied. Increase of the temperature testing from 173 K to 348 K decreases the yield stress by 80 MPa, the ultimate tensile strength by 60 MPa while elongation-to failure increases by a factor of 1.4. It was found that at temperatures of 298 and 173 K, the studied alloy mainly demonstrates the mode of ductile fracture, and at a temperature of 348 K the mechanism can be described as mixed ductile-brittle fracture. It was also established that of the studied alloy is the temperature dependence of the size of the dimples on the fracture surface. The formation of smaller dimples in the samples deformed at 298 K was observed.

Study on Machining of Cracking Notches for Automotive Connecting Rod Using WEDM

2010 ◽  
Vol 447-448 ◽  
pp. 228-232
Author(s):  
Yong Jun Tang ◽  
Yuan Bo Li ◽  
Yong Jun Zhang ◽  
Chun Qiang Zhou
Keyword(s):  
Cutting Speed ◽  
Connecting Rod ◽  
Electric Discharge Machine ◽  
Fracture Splitting ◽  
Discharge Machine ◽  
Wire Electric Discharge Machine ◽  
The Cost ◽  
The Relationship ◽  
In Virtue Of ◽  
Splitting Process

In order to resolve the problem of connecting rod notches machining, a new process of WEDM (Wire Electric Discharge Machine) has been presented, and it is greatly possible that expensive laser process can be replaced by WEDM in virtue of its unique advantages. Firstly, process parameters of notch have been analyzed, and project of machining notch using WEDM has been introduced, including measures to achieve good-quality notch. The relationship between cutting speed and power supply parameters has been investigated, and it is discovered that micro-crackle on bottom of notch are greatly effect to fracture splitting process, also new idea of active controlling micro-crackle has been presented. Finally, fracture splitting machining has been carried out. The cost and entrance standard of fracture splitting process are greatly dropped owing to new breakthrough of machining notch using WEDM.

The Microscopic Analysis on the Crankshaft Fracture Surface of the Compressor

2014 ◽  
Vol 912-914 ◽  
pp. 837-840
Author(s):  
Wei Dong Chen
Keyword(s):  
Heat Treatment ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Grain Refinement ◽  
Stress Fracture ◽  
Failure Modes ◽  
Microscopic Analysis ◽  
Dendritic Segregation ◽  
Micro Analysis

Fracture is the most common failure modes of the crankshaft, under normal circumstances often result in serious consequences. So study the reasons for the crankshaft fracture, thus achieving the purpose of controlling and reducing accidents, is very realistic. In this paper, for example, a factory break 4M16 compressor crankshaft. Through micro-analysis of the crankshaft fracture, the 4M16 compressor crankshaft is a low stress fracture of brittle fracture .The fracture is mainly due to dendritic segregation cause tissue caused by uneven. Solution to the problem is to increase the ratio of forging the forging, heat treatment when the grain refinement.

Effects of nanoparticles on properties and interface reaction of Sn solder for microelectronic packaging

2020 ◽  
Vol 34 (08) ◽  
pp. 2050064 ◽  
Author(s):  
Meng Zhao ◽  
Liang Zhang ◽  
Lei Sun ◽  
Ming-yue Xiong ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Melting Point ◽  
Composite Solder ◽  
Interface Reaction ◽  
Microelectronic Packaging ◽  
Cu Nanoparticles ◽  
Spreading Area ◽  
Melting Characteristics ◽  
Interfacial Intermetallic Compounds

In this study, the effects of Cu nanoparticles on the melting characteristics, wettability, interfacial reaction and mechanical properties of [Formula: see text]–[Formula: see text] [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] composite solders were investigated. Results show that the properties of the composite solder containing Cu nanoparticles were improved effectively. With the addition of Cu nanoparticles, the melting point of [Formula: see text]–[Formula: see text] solder decreased significantly, and the spreading area and the shear strength were increased by 10.3% and 23.2%, respectively. For the performance, the optimal addition of Cu nanoparticles was 0.7%. In addition, the growth of interfacial intermetallic compounds in [Formula: see text]–[Formula: see text] solder joints was inhibited by adding Cu nanoparticles.

The Effect of the Fracture Surface for Stress Sensitivity in Shale Reservoir

2013 ◽  
Vol 779-780 ◽  
pp. 1427-1430
Author(s):  
Jin Gang He ◽  
Kao Ping Song ◽  
Jing Yang ◽  
Song He ◽  
Li Yan Sun ◽  
...  
Keyword(s):  
Fracture Surface ◽  
Rock Sample ◽  
Three Dimensional ◽  
Stress Sensitivity ◽  
Natural Fracture ◽  
Imaging Method ◽  
Fracture Rock ◽  
Structure Information ◽  
Sem Image ◽  
Artificial Fracture

Due to the characteristics of the ultra-low permeability, facture system becomes the key to the deployment of shale gas, and the following stress sensitivity damage will restrict the engineering effect. The essay takes the Niutitang group of black shale as the research object, which carried out for natural fracture rock sample and artificial fracture rock sample study of stress sensitivity evaluation in order to compare differences between them. The experimental results show that the natural fracture rock sample is medium to strong stress sensitivity, while the artificial fracture rock sample is from strong to the extreme strong stress sensitivity. Natural fracture is more flattening than the artificial fracture formation because of leaching action. The processed SEM image can reflect structure information on the two-dimensional surface. Its surface structure conforms to the fractal structure characteristics. Whats more, fracture it can also reflect the three-dimensional information of the fracture surface through grey value, which provides a new imaging method for the research of surface microstructure for fracture.

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