scholarly journals Fabrication of Metal Matrix Composite by Laser Metal Deposition—A New Process Approach by Direct Dry Injection of Nanopowders

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3584 ◽  
Author(s):  
Briac Lanfant ◽  
Florian Bär ◽  
Antaryami Mohanta ◽  
Marc Leparoux
Keyword(s):  
Metal Matrix ◽  
Metallic Matrix ◽  
Process Approach ◽  
Metal Deposition ◽  
Al2o3 Nanoparticles ◽  
Laser Metal Deposition ◽  
Metal Matrix Nanocomposites ◽  
X Ray ◽  
New Process

Laser Metal Deposition (LMD) offers new perspectives for the fabrication of metal matrix nanocomposites (MMnCs). Current methods to produce MMnCs by LMD systematically involve the premixing of the nanopowders and the micropowders or require in-situ strategies, thereby restricting the possibilities to adjust the nature, content and location of the nano-reinforcement during printing. The objective of this study is to overcome such restrictions and propose a new process approach by direct injection of nanoparticles into a metallic matrix. Alumina (n-Al2O3) nanoparticles were introduced into a titanium matrix by using two different direct dry injection modes in order to locally increase the hardness. Energy dispersive X-ray spectroscopy (EDS) analyses validate the successful incorporation of the n-Al2O3 at chosen locations. Optical and high resolution transmission electron microscopic (HR-TEM) observations as well as X-ray diffraction (XRD) analyses indicate that n-Al2O3 powders are partly or totally dissolved into the Ti melted pool leading to the in-situ formation of a composite consisting of fine α2 lamellar microstructure within a Ti matrix and a solid solution with oxygen. Mechanical tests show a significant increase in hardness with the increase of injected n-Al2O3 amount. A maximum of 620 HV was measured that is almost 4 times higher than the pure LMD-printed Ti structure.

Effect of Composition on the Morphology and Hardness of Nanostructured Cu Based Composite and Alloy Powders/Granules Produced by High Energy Mechanical Milling

2007 ◽  
Vol 29-30 ◽  
pp. 143-146 ◽  
Author(s):  
Aamir Mukhtar ◽  
De Liang Zhang ◽  
C. Kong ◽  
P. R. Munroe
Keyword(s):  
Grain Size ◽  
Mechanical Milling ◽  
Alloy Powder ◽  
High Energy ◽  
Al2o3 Nanoparticles ◽  
X Ray ◽  
Fine Powders ◽  
Average Grain Size ◽  
Powder Particles

Cu-(2.5 or 5.0vol.%)Al2O3 nanocomposite balls and granules and Cu-(2.5vol.% or 5.0vol.%)Pb alloy powder were prepared by high energy mechanical milling (HEMM) of mixtures of Cu and either Al2O3 or Pb powders. It was observed that with the increase of the content of Al2O3 nanoparticles from 2.5vol.% to 5vol.% in the powder mixture, the product of HEMM changed from hollow balls into granules and the average grain size and microhardness changed from approximately 130nm and 185HV to 100nm and 224HV, respectively. On the other hand, HEMM of Cu–(2.5 or 5.0vol.%) Pb powder mixtures under the same milling conditions failed to consolidate the powder in-situ. Instead, it led to formation of nanostructured fine powders with an average grain size of less than 50nm. Energy dispersive X-ray mapping showed homogenous distribution of Pb in the powder particles in Cu–5vol.%Pb alloy powder produced after 12 hours of milling. With the increase of the Pb content from 2.5 to 5.0 vol.%, the average microhardness of the Cu-Pb alloy powder particles increases from 270 to 285 HV. The mechanisms of the effects are briefly discussed.

Ultrasonic Attenuation Based Inspection Method for Scale-up Production of A206–Al2O3 Metal Matrix Nanocomposites

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Jianguo Wu ◽  
Shiyu Zhou ◽  
Xiaochun Li
Keyword(s):  
Metal Matrix ◽  
High Performance ◽  
Ultrasonic Attenuation ◽  
Hypothesis Test ◽  
Scale Up ◽  
Al2o3 Nanoparticles ◽  
Quality Inspection ◽  
Ultrasonic Dispersion ◽  
Inspection Method ◽  
Metal Matrix Nanocomposites

A206–Al2O3 metal matrix nanocomposite (MMNC) is a promising high performance material with potential applications in various industries, such as automotive, aerospace, and defense. Al2O3 nanoparticles dispersed into molten Al using ultrasonic cavitation technique can enhance the nucleation of primary Al phase to reduce its grain size and modify the secondary intermetallic phases. To enable a scale-up production, an effective yet easy-to-implement quality inspection technique is needed to effectively evaluate the resultant microstructure of the MMNCs. At present the standard inspection technique is based on the microscopic images, which are costly and time-consuming to obtain. This paper investigates the relationship between the ultrasonic attenuation and the microstructures of pure A206 and Al2O3 reinforced MMNCs with/without ultrasonic dispersion. A hypothesis test based on an estimated attenuation variance was developed and it could accurately differentiate poor samples from good ones. This study provides useful guidelines to establish a new quality inspection technique for A206–Al2O3 nanocomposites using ultrasonic nondestructive testing method.

scholarly journals In Situ Stress Tensor Determination during Phase Transformation of a Metal Matrix Composite by High-Energy X-ray Diffraction

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1415 ◽  
Author(s):  
Guillaume Geandier ◽  
Lilian Vautrot ◽  
Benoît Denand ◽  
Sabine Denis
Keyword(s):  
Phase Transformation ◽  
Stress Tensor ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
High Energy ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray

In situ high-energy X-ray diffraction using a synchrotron source performed on a steel metal matrix composite reinforced by TiC allows the evolutions of internal stresses during cooling to be followed thanks to the development of a new original experimental device (a transportable radiation furnace with controlled rotation of the specimen). Using the device on a high-energy beamline during in situ thermal treatment, we were able to extract the evolution of the stress tensor components in all phases: austenite, TiC, and even during the martensitic phase transformation of the matrix.

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.

Cladding of Stellite-6/WC Composites Coatings by Laser Metal Deposition

2018 ◽  
Vol 941 ◽  
pp. 1645-1650 ◽  
Author(s):  
Takahiro Kunimine ◽  
Ryusei Miyazaki ◽  
Yorihiro Yamashita ◽  
Yoshinori Funada ◽  
Yuji Sato ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Metal Deposition ◽  
Matrix Composites ◽  
Laser Metal Deposition ◽  
Feeding Rates ◽  
Coating Materials ◽  
Cross Sectional ◽  
Stellite 6 ◽  
Powder Feeding

This study aims to investigate the microstructure and hardness of multi-layered Stellite-6/WC metal-matrix composites coatings on metallic substrates cladded by laser metal deposition (LMD) for improvement of wear and corrosion resistances. As coating materials, Stellite-6 and WC-12wt.%Co powders were selected. Powder mixtures having various mixing-ratios of Stellite-6 and WC-12wt.%Co were provided vertically on S45C substrates by controlling powder feeding rates of the two powder feeders, individually. Stellite-6/WC composites which consist of three layers with different compositions were cladded on the S45C substrates by laser melting. Cross-sectional microstructure observation was carried out by using an optical microscope (OM). Vickers microhardness tests were conducted to evaluate hardness of the cladding layers and substrates. The experimental results demonstrate that hard multi-layered Stellite-6/WC metal-matrix composites coatings were successfully cladded on the S45C substrates. Property gradients in the Stellite-6/WC composites could be made due to the position-dependent chemical composition and microstructure made by controlling powder feeding rates of an LMD system.

scholarly journals In-situ Monitoring and Defect Detection for Laser Metal Deposition by Using Infrared Thermography

2016 ◽  
Vol 83 ◽  
pp. 1244-1252 ◽  
Author(s):  
Ulf Hassler ◽  
Daniel Gruber ◽  
Oliver Hentschel ◽  
Frank Sukowski ◽  
Tobias Grulich ◽  
...  
Keyword(s):  
Infrared Thermography ◽  
Defect Detection ◽  
Metal Deposition ◽  
In Situ Monitoring ◽  
Laser Metal Deposition

Impact of X-Ray Tomographic Microscopy on Deformation Studies of a SiC/Al MMC

1990 ◽  
Vol 217 ◽  
Author(s):  
T.M. Breunig ◽  
S.R. Stock ◽  
J.H. Kinney ◽  
A. Guvenilir ◽  
M.C. Nichols
Keyword(s):  
Metal Matrix ◽  
Three Dimensional ◽  
Structural Stiffness ◽  
Hexagonal Array ◽  
Fiber Fracture ◽  
X Ray ◽  
Damage Quantification ◽  
Dimensional Measurements ◽  
Irregular Arrangement

ABSTRACTDamage in a continuous, aligned-fiber SiC/Al metal matrix composite (MMC), e.g. fiber fracture, fiber-matrix interphase microcracking, intra-ply matrix voids and cracks, is examined with synchrotron x-ray tomographic microscopy (XTM). Quantitative three-dimensional measurements of damage are reported in as-fabricated and monotonically loaded SiC/Al. The XTM results indicate that increases in observed macroscopic structural stiffness during the first few fatigue cycles of an MMC coupon correspond to elimination of processing-related matrix porosity and to displacement of the fibers from a somewhat irregular arrangement into a more nearly hexagonal array. The XTM data also show that the carbon cores of the SiC fibers begin to fail at or below 828 MPa, that is, at loads far less than those for fracture of the entire fiber. The implications of these results and of the use of in situ loading for fatigue damage quantification are also discussed for mechanical/thermal modelling.

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