scholarly journals Microstructure and Mechanical Properties of Al-12Si Alloys Fabricated by Ultrasonic-Assisted Laser Metal Deposition

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 126 ◽  
Author(s):  
Yang Zhang ◽  
Yuqi Guo ◽  
Yan Chen ◽  
Yabin Cao ◽  
Haibo Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Ultrasonic Vibration ◽  
Molten Pool ◽  
Maximum Size ◽  
Metal Deposition ◽  
Ultrasonic Power ◽  
Laser Metal Deposition ◽  
Ultrasonic Assisted ◽  
Metallographic Observation

This paper presents a method of ultrasonic-assisted laser metal deposition of Al-12Si alloy. The effects of the ultrasonic power and remelting treatment on the development of porosity, microstructural evolution, and tensile properties of the deposits were investigated. The results suggested that a combination of an ultrasonic vibration and remelting treatment could prolong the existence of the molten pool and the effect of the ultrasound. Therefore, the density of the samples increased from 95.4% to 99.1% compared to the as-prepared samples. The ultrasonic action in the molten pool could not only increase the density of the samples but also refine the grains and improve the tensile properties of the samples. Metallographic observation showed that the maximum size of the primary α-Al dendrites were refined from 277.5 µm to 87.5 µm. The ultimate tensile strength and elongation of the remelting treatment samples with ultrasonic vibration were ~227 ± 3 MPa and 12.2% ± 1.4%, respectively, which were approximately 1.17 and 1.53 times those of the as-prepared samples, respectively. According to the tensile properties and fracture analysis, the density increase dominated the improvement of the mechanical properties.

scholarly journals Ultrasonic-Assisted Laser Metal Deposition of the Al 4047Alloy

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1111 ◽  
Author(s):  
Zhang ◽  
Guo ◽  
Chen ◽  
Kang ◽  
Cao ◽  
...  
Keyword(s):  
Relative Density ◽  
Laser Power ◽  
Tensile Ductility ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Ultrasonic Power ◽  
Laser Metal Deposition ◽  
Ultrasonic Assisted ◽  
Cast Alloys ◽  
Cast Parts

Ultrasonic-assisted laser metal deposition(UALMD) technology was used to fabricate Al 4047 parts. The effect of the powder feeding laser power, remelting laser power and ultrasonic power on the relative density of the parts was investigated. The relative density, microstructure and mechanical properties of the specimens obtained by the optimized process parameters were compared with the corresponding properties of the cast alloys. The results showed that dense alloys with a maximum density of 99.1% were prepared using ultrasonic vibration and by remelting the previously deposited layer with the optimized processing parameters, and its density was almost equivalent to that of the cast parts. The microstructure of the samples using optimal laser parameters presented columnar Al dendrites and equiaxed Si particles at the boundary of each deposited layer, while the supersaturated Al solid solution was transformed into equiaxed crystal surrounded by fine fibrous Si phases at the center of the layer. Moreover, the size of the primary Al and the Si particles in the samples produced by UALMD was remarkably refined compared to that of the primary Al and Si particles in the cast structure, resulting in grain refining strengthening. The observed variation in the microstructure had an obvious impact on the tensile properties. The mechanical behavior of the deposit obtained by UALMD revealed superior tensile strength, yield strength and tensile ductility values of 227 ± 3 MPa, 107 ± 4 MPa and 12.2 ± 1.4%, which were approximately 51%, 38% and 56% higher than those of the cast materials, respectively.

Preliminary Experimental Study of Warm Ultrasonic Impact-assisted Laser Metal Deposition

2021 ◽  
pp. 1-15
Author(s):  
Hanyu Song ◽  
Minglang Li ◽  
Muxuan Wang ◽  
Benxin Wu ◽  
Ze Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Solid Material ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Ultrasonic Impact Treatment ◽  
Post Process ◽  
Underlying Mechanisms ◽  
Manufacturing Time

Abstract A preliminary experimental study on “warm ultrasonic impact-assisted laser metal deposition” (WUI-LMD) is reported, and such a study is rare in literatures to the authors' knowledge. In WUI-LMD, an ultrasonic impact treatment (UIT) tip is placed near laser spot for in-situ treatment of laser-deposited warm solid material, and the UIT and LMD processes proceed simultaneously. Under the conditions investigated, it is found that in-situ UIT during WUI-LMD can be much more effective in reducing porosity than a post-process UIT. Possible underlying mechanisms are analyzed. WUI-LMD has a great potential to reduce defects and improve mechanical properties without increasing manufacturing time.

Optimizing Ultrasonic Power on Fabricating Aluminum Nanocomposites Reinforced with Boron Carbide Nanoparticles

2020 ◽  
Vol 979 ◽  
pp. 28-33 ◽  
Author(s):  
Lakshmanan Poovazhgan ◽  
S. Vijayananth ◽  
S. Sivaganesan
Keyword(s):  
Mechanical Properties ◽  
Boron Carbide ◽  
Microstructural Analysis ◽  
Casting Process ◽  
Al Alloy ◽  
Ultrasonic Power ◽  
Metal Matrix Nanocomposites ◽  
Ultrasonic Assisted ◽  
Matrix Nanocomposites ◽  
Power Play

In this work, aluminum (Al) alloy reinforced with boron carbide (B4C) nanoparticles were fabricated using ultrasonic assisted casting process. To investigate the effect of ultrasonic power on processing the metal matrix nanocomposites (MMNCs), the MMNC samples were processed with 1.0 kW, 1.5 kW and 2.0 kW of ultrasonic power. The results indicate that the ultrasonic power play a significant role in dispersing the B4C nanoparticles uniformly in Al melt and it also affects the mechanical properties of the fabricated MMNCs. From microstructural analysis it was observed that the MMNC sample processed with 2.0 kW ultrasonic powers possessed the good dispersion of B4C in the Al melt which is the prime criteria for the good mechanical properties.

scholarly journals Interface Characteristics and Mechanical Properties of Ultrasonic-Assisted Friction Stir Lap Welded 7075-T6 Aluminium Alloy

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5335 ◽  
Author(s):  
Changshu He ◽  
Zhiqiang Zhang ◽  
Ying Li ◽  
Jingxun Wei ◽  
Menggang Zhai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Vibration ◽  
Fracture Mode ◽  
Fracture Strength ◽  
Shear Fracture ◽  
Friction Stir Lap Welding ◽  
Friction Stir ◽  
Ultrasonic Assisted ◽  
Lap Welding ◽  
Cold Lap

In this work, friction stir lap welding (FSLW) and ultrasonic-assisted friction stir lap welding (UAFSLW) was applied to 6-mm-thick 7075-T6 alloy sheets using three welding tools with the same process parameters. The joint formation, microstructural characteristics, and mechanical properties of the resulting lap joints were then investigated. The results showed that ultrasonic vibration significantly promoted the flow of metal at the interface, enlarged the size of the stirred zone (SZ), and reduced the angle between the hook defect and the interface. During lap shear testing, the FSLW and UAFSLW joints fractured in a similar manner. The fracture modes included tensile fracture, shear fracture, and a mixture of both. Cold lap and hook defects may have served as crack-initiation zones within the joint. Under configuration A (i.e., upper sheet on the retreating side (RS)), all joints failed in the shear-fracture mode. The effective lap width (ELW) of the joint welded using tool T2 was the greatest. This resulted in a higher shear fracture strength. The maximum shear fracture strength of the UAFSLW joint was 663.1 N/mm. Under configuration B (i.e., upper sheet on the advancing side (AS)), the shear fracture strength was greatly affected by the fracture mode. The highest shear fracture strength of the UAFSLW joint, 543.7 N/mm, was welded by tool T3. Thus, under otherwise identical conditions, UAFSLW joints can withstand a greater fracture shear strength than FSLW joints, as ultrasonic vibration helps to mix the material at the interface, thus, enlarging the SZ and diminishing the cold lap defects.

Experimental Study on Laser Metal Deposition of FGMs with Ultrasonic Vibration

2012 ◽  
Vol 271-272 ◽  
pp. 131-135 ◽  
Author(s):  
Lan Yun Qin ◽  
Wei Wang ◽  
Guang Yang
Keyword(s):  
Ultrasonic Vibration ◽  
Metal Deposition ◽  
Functionally Graded ◽  
Laser Metal Deposition ◽  
Vibration System ◽  
Hard Phase ◽  
Graded Materials ◽  
Vibration Effect ◽  
Distribution Uniformity ◽  
Microstructure And Mechanical Property

Referring to the ultrasonic vibration effect on casting, welding and laser cladding, the paper demonstrates the feasibility that it can be also used in Laser Metal Deposition(LMD)of titanium alloy to protect the defects such as crack,pore and oxidation and refine the grain size and improve the distribution uniformity of solidified structure.So the paper applies ultrasonic vibration system to fabricate the functionally graded materials(FGMs) samples and analyses its effect on the specimen microstructure and mechanical property by experiments.The results show that ultrasonic vibration can suppress the formation of pore、refine the grain and make the TiC hard phase more homogeneous in the FGMs parts, which is also indicated by the microhardness tests

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