scholarly journals Microstructure and Mechanical Properties of Tungsten Inert Gas Weld Joints of Sprayed and Cast Aluminium–Lithium Alloy

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3787
Author(s):  
Chuanguang Luo ◽  
Huan Li ◽  
Yuhui Zhang ◽  
Jianguo Li ◽  
Yuanhua Wen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fracture Mode ◽  
Inert Gas ◽  
Tensile Fracture ◽  
Second Phase ◽  
Tensile Fracture Surface ◽  
Weld Joints ◽  
Lithium Alloy ◽  
Mixed Fracture

The weld joints of sprayed 2195-T6 and cast 2195-T8 aluminium–lithium alloy were created using tungsten inert gas with filler wire. The microstructures and mechanical properties of the weld joints were examined. The results of the microstructure analysis showed that the width of the equiaxed grain zone (EQZ) and the amount of the second phase θ’(Al2Cu) was greater in the weld joint of the cast 2195-T8 Al–Li alloy than that of the sprayed 2195-T6 Al–Li alloy. Tensile testing indicated that failures occurred in the EQZ and partially melted zone (PMZ) for both weld joints. The tensile strength and elongation of the weld joints of the sprayed 2195-T6 and cast 2195-T8 Al–Li alloys were about 68.2%, 89.7%, and 50.7% and 28.3% those of the base metal in the joint, respectively. The cast 2195-T8 Al–Li alloy joint had more pores and cracks, resulting in lower tensile strength and elongation than those in the sprayed alloy. Further, the tensile fracture surface morphology indicated that the fracture mode of the sprayed 2195-T6 Al–Li alloy was a mixed fracture mode dominated by plastic fracture and that of the cast 2195-T8 Al–Li alloy joints was a mixed fracture mode dominated by brittle fracture.

scholarly journals Impacts of Defocusing Amount and Molten Pool Boundaries on Mechanical Properties and Microstructure of Selective Laser Melted AlSi10Mg

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 73 ◽  
Author(s):  
Suyuan Zhou ◽  
Yang Su ◽  
Rui Gu ◽  
Zhenyu Wang ◽  
Yinghao Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Molten Pool ◽  
Tensile Ductility ◽  
Processing Parameters ◽  
Coarse Grain ◽  
Tensile Fracture ◽  
High Tensile Strength ◽  
Laser Melting ◽  
Tensile Fracture Surface

The influences of processing parameters such as volumetric energy density (ε) and, particularly, defocusing amount (DA) on densification, microstructure, tensile property, and hardness of the as-printed dense AlSi10Mg alloy by selective laser melting (SLM) were studied systematically. The molten pool boundaries (MPBs) were found overwhelmingly at regular and complex spatial topological structures affected by DA value to exist in two forms, while the “layer–layer” MPB overlay mutually and the “track–track” MPBs intersect to form acute angles with each other. The microstructure of MPBs exhibits a coarse grain zone near the MPBs and the characteristics of segregation of nonmetallic elements (O, Si) where the crack easily happened. The DA value (−2 to 2 mm) affected both the density and the tensile mechanical properties. High tensile strength (456 ± 14 MPa) and good tensile ductility (9.5 ± 1.4%) were achieved in the as-printed condition corresponding to DA = 0.5 mm. The tensile fracture surface features were analyzed and correlated to the influence of the DA values.

Microstructure and mechanical properties of reinforced polyamide 12 composites prepared by laser additive manufacturing

2019 ◽  
Vol 25 (6) ◽  
pp. 1127-1134 ◽  
Author(s):  
Yanhui Liu ◽  
Lingjie Zhu ◽  
Lei Zhou ◽  
Yongjiu Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Selective Laser Sintering ◽  
Tensile Fracture ◽  
Fracture Mechanisms ◽  
Strengthening Effect ◽  
Content Type ◽  
Tensile Fracture Surface ◽  
Polyamide 12 ◽  
Microstructure And Mechanical Properties

Purpose This paper aims to explore the influence of the reinforcement included either glass beads (GBs) or carbon fiber (CF) on the reinforced polyamide 12 (PA12) composite samples prepared by selective laser sintering (SLS). Design/methodology/approach In this paper, the microstructure and mechanical properties are investigated, and the results are compared with those obtained for non-reinforced pure PA12 samples prepared by SLS. Findings The tensile fracture surface of the non-reinforced pure PA12 sample presents strong micro-deformation within the crack origination zone between the melted PA12 matrix and the un-melted PA12 particle cores. As a result, the pure PA12 sample exhibits the greatest maximum elongation. The maximum tensile strength is obtained for the CF reinforced sample because of the strengthening effect of CF and the relatively good bonding between CFs and the PA12 matrix. The minimum tensile strength is obtained for the GB reinforced PA12 sample because of the relatively weak bonding between GBs and the PA12 matrix. Originality/value These results demonstrate that the characteristics of the interfaces between the reinforcement and the PA12 matrix have an important influence on the fracture mechanisms and mechanical properties of PA12 composites fabricated by SLS.

The Influence of Specific Pressure on the Organization and Properties in Liquid Forging

2012 ◽  
Vol 430-432 ◽  
pp. 598-601
Author(s):  
Chun Li ◽  
Jia Xuan Wang ◽  
Hua Qing Miao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fracture Surface ◽  
Process Parameters ◽  
Tensile Fracture ◽  
Specific Pressure ◽  
Tensile Fracture Surface ◽  
Forging Process ◽  
Fracture Surface Analysis ◽  
And Performance

In this paper, based on the liquid forging part flange LY12, the influence of specific pressure on the organization and performance of the liquid forging part was studied through microstructure, mechanical properties and tensile fracture surface analysis methods, this article also has some guiding significance to the formulation of the best liquid forging process parameters. The results show that the tensile strength, hardness and elongation of the parts raise with the specific pressure increasing, the organization has also been significant refinement and improvement.

Effect of Rare Earth Addition on Microstructure and Mechanical Properties of Al-Si Alloys: An Overview

2013 ◽  
Vol 845 ◽  
pp. 27-30 ◽  
Author(s):  
S.L. Joy-Yii ◽  
Denni Kurniawan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Rare Earth ◽  
Earth Element ◽  
Wear Behaviour ◽  
Tensile Fracture ◽  
Tensile Fracture Surface ◽  
Primary Si ◽  
Rare Earth Addition

This paper reviews the effect of rare earth addition on aluminium-silicon (Al-Si) alloys of hypoeutectic, eutectic, and hypereutectic types. The effects of rare earth on metallurgy, tensile strength, tensile fracture surface and wear behaviour of Al-Si alloys are highlighted and discussed in this paper. It was concluded that adding rare earth element to Al-Si alloys reduces the grain size of primary Si, increases the tensile strength and decreases the friction coefficient decreases. These indicate enhanced mechanical properties for rare earth modified Al-Si alloys are likely.

scholarly journals Microstructural Characteristics and Mechanical Properties of Friction Stir Spot Welded 2A12-T4 Aluminum Alloy

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Huijie Liu ◽  
Yunqiang Zhao ◽  
Xingye Su ◽  
Lilong Yu ◽  
Juncai Hou
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Fracture Mode ◽  
Heat Input ◽  
Tensile Shear ◽  
Microstructural Characteristics ◽  
Friction Stir ◽  
Welding Heat Input ◽  
Mixed Fracture ◽  
Spot Welded

2A12-T4 aluminum alloy was friction stir spot welded, and the microstructural characteristics and mechanical properties of the joints were investigated. A softened microstructural region existed in the joint, and it consisted of stir zone (SZ), thermal mechanically affected zone (TMAZ), and heat affected zone (HAZ). The minimum hardness was located in TMAZ, and the average hardness value in SZ can be improved by appropriately increasing welding heat input. The area of complete bonding region at the interface increased with increasing welding heat input because more interface metals were mixed. In a certain range of FSSW parameters, the tensile shear failure load of the joint increased with increasing rotation speed, but it decreased with increasing plunge rate or decreasing shoulder plunging depth. Two kinds of failure modes, that is, shear fracture mode and tensile-shear mixed fracture mode, can be observed in the tensile shear tests, and the joint that failed in the tensile-shear mixed fracture mode possessed a high carrying capability.

Influence of Plastic Deformation on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 1082-1086
Author(s):  
Yao Jin Wu ◽  
Zhi Ming Zhang ◽  
Bao Cheng Li ◽  
Bao Hong Zhang ◽  
Jian Min Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Grain Boundaries ◽  
Gradual Increase ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Second Phase ◽  
Az80 Magnesium Alloy ◽  
Strength And Plasticity

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperature (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure changes of AZ80 magnesium alloy have been investigated through tensile test and via ZEISS digital metallographic microscope observation. Research indicates that the alloy’s plasticity gradually decreases as the temperature increases, and that the alloy’s tensile strength varies with the extrusion ratio. At 330°C, the alloy’s particle grain is small and a small amount of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390 Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, both the tensile strength and plasticity increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.

Effect of Plastic Deformation on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 180-184
Author(s):  
Yong Xue ◽  
Zhi Min Zhang ◽  
Li Hui Lang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundaries ◽  
Gradual Increase ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Second Phase ◽  
Strength And Plasticity ◽  
Az80 Alloy

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperatures (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure of homogenized AZ80 alloy have been investigated through the tensile tests and via metallographic microscope observation. The results show that the alloy’s grain is small and small amounts of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength at 330°C. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, the tensile strength increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.

scholarly journals Preparation and Mechanical Properties of ZK61-Y Magnesium Alloy Wheel Hub via Liquid Forging—Isothermal Forging Process

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 385
Author(s):  
Yushi Qi ◽  
Heng Wang ◽  
Lili Chen ◽  
Hongming Zhang ◽  
Gang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Heat Treatments ◽  
Second Phase ◽  
Phase Hardening ◽  
Isothermal Forging ◽  
Forging Process ◽  
Microstructure And Mechanical Properties ◽  
Alloy Wheel

A ZK61-Y magnesium (Mg) alloy wheel hub was prepared via liquid forging—isothermal forging process. The effects of Y-element contents on the microstructure and mechanical properties of liquid forging blanks were investigated. The formation order of the second phase was I-phase (Mg3Zn6Y) → W-phase (Mg3Zn3Y2) → Z-phase (Mg12ZnY) with the increase of the Y-element content. Meanwhile, the I-phase and Z-phase formed in the liquid forging process were beneficial to the grain refinement. The numerical simulation of the isothermal forging process was carried out to analyze the effects of forming temperature on the temperature and stress field in the forming parts using the software Deform-3D. Isothermal forging experiments and post heat treatments were conducted. The influence of isothermal forging temperature, heat treatment temperature and preservation time on the microstructure and mechanical properties of the forming parts were also studied. The dynamic recrystallization (DRX), second-phase hardening, and work hardening account for the improvement of properties after the isothermal forging process. The forming part forged at 380 °C displayed the outstanding properties. The elongation, yield strength, and ultimate tensile strength were 18.5%, 150 MPa and 315 MPa, respectively. The samples displayed an increased elongation and decreased strength after heat treatments. The 520 °C—1 h sample possessed the best mechanical properties, the elongation was 25.5%, the yield stress was 125 MPa and the ultimate tensile strength was 282 MPa. This can be ascribed to the recrystallization and the elimination of working hardening. Meanwhile, the second phase transformation (I-phase → W-phase → Mg2Y + MgZn2), dissolution, and decomposition can be observed, as well.

scholarly journals Mechanical Properties of Welt Knitted Fabric Reinforced Composites

1995 ◽  
Vol 4 (3) ◽  
pp. 096369359500400 ◽  
Author(s):  
Hiroyuki Hamada ◽  
Asami Nakai ◽  
Akihiro Fujita ◽  
Miyako Inoda
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Fracture Mode ◽  
Knitted Fabric ◽  
Reinforced Composites ◽  
Reinforced Composite ◽  
Plain Knitted Fabric ◽  
Knitted Structure

In this paper, welt knitted fabric reinforced composites were fabricated and its tensile properties were measured. Changing knitted structure from plain knit to welt knit caused changing mechanical properties, particularly isotropic tensile strength could be obtained. The fracture mode of welt knitted fabric reinforced composite was similar that of plain knitted fabric reinforced composite.

scholarly journals The Effect of Process Parameters on the Microstructure and Mechanical Properties of AW5083 Aluminum Laser Weld Joints

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1443 ◽  
Author(s):  
Maroš Vyskoč ◽  
Miroslav Sahul ◽  
Mária Dománková ◽  
Peter Jurči ◽  
Martin Sahul ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Process Parameters ◽  
Flow Rate ◽  
Weld Joint ◽  
Gas Flow ◽  
Filler Wire ◽  
Shielding Gas ◽  
Gas Flow Rate ◽  
Weld Joints

In this article, the effect of process parameters on the microstructure and mechanical properties of AW5083 aluminum alloy weld joints welded by a disk laser were studied. Butt welds were produced using 5087 (AlMg4.5MnZr) filler wire, with a diameter of 1.2 mm, and were protected from the ambient atmosphere by a mixture of argon and 30 vol.% of helium (Aluline He30). The widest weld joint (4.69 mm) and the highest tensile strength (309 MPa) were observed when a 30 L/min shielding gas flow rate was used. Conversely, the narrowest weld joint (4.15 mm) and the lowest tensile strength (160 MPa) were found when no shielding gas was used. The lowest average microhardness (55.4 HV0.1) was recorded when a 30 L/min shielding gas flow rate was used. The highest average microhardness (63.9 HV0.1) was observed when no shielding gas was used. In addition to the intermetallic compounds, β-Al3Mg2 and γ-Al12Mg17, in the inter-dendritic areas of the fusion zone (FZ), Al49Mg32, which has an irregular shape, was recorded. The application of the filler wire, which contains zirconium, resulted in grain refinement in the fusion zone. The protected weld joint was characterized by a ductile fracture in the base material (BM). A brittle fracture of the unshielded weld joint was caused by the presence of Al2O3 particles. The research results show that we achieved the optimal welding parameters, because no cracks and pores were present in the shielded weld metal (WM).

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