scholarly journals Tribological Behavior of TiC Particles Reinforced 316Lss Composite Fabricated Using Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 950 ◽  
Author(s):  
Jing Li ◽  
Zhanyong Zhao ◽  
Peikang Bai ◽  
Hongqiao Qu ◽  
Minjie Liang ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
High Speed ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Tribological Behavior ◽  
Friction Material ◽  
Bearing Steel ◽  
Laser Melting ◽  
Delamination Wear ◽  
The Matrix

In order to improve the abrasion performance of 316Lss, make full use of its advantages and broaden its application fields, the tribological behavior of the TiC particles reinforced 316Lss composites—which were manufactured by selective laser melting (SLM)—were investigated. In this study, GCr15 bearing steel was selected as the friction material and experiments on the sliding friction and wear under different loads of 15 N, 25 N and 35 N at the sliding speeds of 60, 80 and 100 mm/min were carried out, respectively. The results show that the wear performance of the TiC/316Lss composite is higher than that of the matrix during the friction and wear experiments under all conditions and the wear rate of the TiC/316Lss composite decreases with increasing the friction rate. Similar to the wear mechanism under different loads, it changes from abrasive wear to delamination wear and severe oxidative wear. At the same time, the mechanical mixed layer formed at a high speed has a protective effect on the matrix. The reason for this phenomenon is that the mechanical properties of the TiC/316Lss composites are significantly improved due to the addition of TiC particles, the refinement of cells near the TiC particles and the formation of a large number of dislocations. In addition, due to the presence of the TiC particles, the hardness and strength of the TiC/316Lss composites are greatly improved, thus the processing hardening ability of sub-surface has been improved.

Friction and Wear Characteristics of Aluminum Alloy Impregnated Carbon Composite

1999 ◽  
Vol 121 (2) ◽  
pp. 294-300 ◽  
Author(s):  
Hozumi Goto ◽  
Shunji Omori
Keyword(s):  
Aluminum Alloy ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Carbon Composite ◽  
Bearing Steel ◽  
Surface Films ◽  
Wear Characteristics ◽  
The Matrix ◽  
The Coefficient Of Friction ◽  
Friction And Wear Characteristics

Pin-on-disk unidirectional sliding friction and wear experiments for an aluminum alloy impregnated carbon composite in contact with a bearing steel were carried out at various levels of contact load in wet and dry air. The aluminum alloy impregnated carbon composite exhibits better friction and wear characteristics than the matrix materials, aluminum alloy and graphite in wet air. The coefficient of friction and wear rate decrease, especially at high loads in wet air. Graphite, together with metallic and oxidative wear particles, adheres to the disk sliding surface of the bearing steel, resulting in the formation of compacted, uniform surface films. The films prevent metal-to-metal contact, achieving a good sliding friction and wear condition.

scholarly journals Selective Laser Melting of Crack-Free High Density M2 High Speed Steel Parts by Baseplate Preheating

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Karolien Kempen ◽  
Bey Vrancken ◽  
Sam Buls ◽  
Lore Thijs ◽  
Jan Van Humbeeck ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
High Speed ◽  
Crack Formation ◽  
High Speed Steel ◽  
Thermal Gradients ◽  
Laser Melting ◽  
Mechanical And Physical Properties ◽  
The World ◽  
M2 High Speed Steel

Cracks and delamination, resulting from residual stresses, are a barrier in the world of additive manufacturing and selective laser melting (SLM) that prohibits the use of many metals in this field. By preheating the baseplate, thermal gradients are lowered and stresses can be reduced. In this work, some initial tests were performed with M2 high speed steel (HSS). The influence of preheating on density and mechanical and physical properties is investigated. The paper shows many promising results for the production of SLM parts in materials that are very sensitive to crack formation and delamination. When using a preheating of 200 °C, crack-free M2 HSS parts were produced with a relative density of 99.8%.

Properties of aluminum metal matrix composites manufactured by selective laser melting

2021 ◽  
Vol 112 (7) ◽  
pp. 552-564
Author(s):  
Christian Felber ◽  
Florian Rödl ◽  
Ferdinand Haider
Keyword(s):  
Additive Manufacturing ◽  
Aluminum Alloys ◽  
Selective Laser Melting ◽  
Metal Matrix ◽  
High Hardness ◽  
High Strength ◽  
Laser Melting ◽  
Scanning Calorimetry ◽  
Particle Reinforcement ◽  
The Matrix

Abstract The most promising metal processing additive manufacturing technique in industry is selective laser melting, but only a few alloys are commercially available, limiting the potential of this technique. In particular high strength aluminum alloys, which are of great importance in the automotive industry, are missing. An aluminum 2024 alloy, reinforced by Ti-6Al-4V and B4C particles, could be used as a high strength alternative for aluminum alloys. Heat treating can be used to improve the mechanical properties of the metal matrix composite. Dynamic scanning calorimetry shows the formation of Al2Cu precipitates in the matrix instead of the expected Al2CuMg phases due to the loss of magnesium during printing, and precipitation processes are accelerated due to particle reinforcement and additive manufacturing. Strong reactions between aluminum and Ti-6Al-4V are observed in the microstructure, while B4C shows no reaction with the matrix or the titanium. The material shows high hardness, high stiffness, and low ductility through precipitation and particle reinforcement.

scholarly journals Effect of the Solution Temperature on the Precipitates and Grain Evolution of IN718 Fabricated by Laser Additive Manufacturing

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 340 ◽  
Author(s):  
Yu Cao ◽  
Pucun Bai ◽  
Fei Liu ◽  
Xiaohu Hou ◽  
Yuhao Guo
Keyword(s):  
Selective Laser Melting ◽  
Treatment Temperature ◽  
Solution Temperature ◽  
Recrystallization Process ◽  
Laser Melting ◽  
Laser Additive Manufacturing ◽  
Laves Phases ◽  
The Matrix ◽  
In718 Superalloy ◽  
Recrystallized Grain Size

The effects of the solution heat treatment temperature on the precipitates, grain boundary evolution and response of the microhardness of Inconel 718 (IN718) superalloy fabricated by selective laser melting (SLM) were investigated. It was found that: (1) The long-chained Laves phases formed in the as-deposited condition dissolved into the matrix when the solution temperature rises above 980 °C. (2) The width-to-length ratio was maintained at approximately 1.6 when the solution was heated from 980 °C to 1080 °C, and dropped down to 1.03 when heated to 1130 °C. (3) Low-angle grain boundaries kept the same number fraction of 65% from 980 to 1080 °C as the as-deposited condition, and decreased dramatically from 1090 to 1130 °C to 4%. (4) Annealing twin boundaries occurred at 1090 °C with a number fraction of 3%, and quickly increased to 65% when heated to 1130 °C. It is concluded that the static recrystallization of IN718 fabricated by selective laser melting (SLM) occurred at 1090 °C and fast proceeded to full recrystallization at 1130 °C. The forming of annealing twins accompanies the recrystallization process and is an effective way to refine the recrystallized grain size.

scholarly journals Microstructure and Mechanical Properties of Carbides Reinforced Nickel Matrix Alloy Prepared by Selective Laser Melting

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4792
Author(s):  
Tian Xia ◽  
Rui Wang ◽  
Zhongnan Bi ◽  
Rui Wang ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Selective Laser Melting ◽  
High Efficiency ◽  
Matrix Alloy ◽  
Tensile Tests ◽  
Laser Melting ◽  
Haynes 230 ◽  
Transmission Electron ◽  
Room Temperature Yield Strength ◽  
The Matrix

Selective laser melting was used to prepare the ceramic particles reinforced nickel alloy owing to its high designability, high working flexibility and high efficiency. In this paper, a carbides particles reinforced Haynes 230 alloy was prepared using SLM technology to further strengthen the alloy. Microstructures of the carbide particles reinforced Haynes 230 alloy were investigated using electron microscopy (SEM), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). Meanwhile, the tensile tests were carried out to determine the strengths of the composite. The results show that the microstructure of the composite consisted of uniformly distributed M23C6 and M6C type carbides and the strengths of the alloy were higher than the matrix alloy Haynes 230. The increased strengths of the carbide reinforced Haynes 230 alloy (room temperature yield strength 113 MPa increased, ~ 33.2%) can be attributed to the synergy strengthening including refined grain strengthening, Orowan strengthening and dislocation strengthening.

scholarly journals Design Rules for Hybrid Additive Manufacturing Combining Selective Laser Melting and Micromilling

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5753
Author(s):  
David Sommer ◽  
Babette Götzendorfer ◽  
Cemal Esen ◽  
Ralf Hellmann
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
High Speed ◽  
Hybrid Approach ◽  
Laser Melting ◽  
Support Design ◽  
Design Rules ◽  
Geometrical Accuracy ◽  
Design Engineers ◽  
A Charge

We report on a comprehensive study to evaluate fundamental properties of a hybrid manufacturing approach, combining selective laser melting and high speed milling, and to characterize typical geometrical features and conclude on a catalogue of design rules. As for any additive manufacturing approach, the understanding of the machine properties and the process behaviour as well as such a selection guide is of upmost importance to foster the implementation of new machining concepts and support design engineers. Geometrical accuracy between digitally designed and physically realized parts made of maraging steel and dimensional limits are analyzed by stripe line projection. In particular, we identify design rules for numerous basic geometric elements like walls, cylinders, angles, inclinations, overhangs, notches, inner and outer radii of spheres, chamfers in build direction, and holes of different shape, respectively, as being manufactured by the hybrid approach and compare them to sole selective laser melting. While the cutting tool defines the manufacturability of, e.g., edges and corners, the milling itself improves the surface roughness to Ra < 2μm. Thus, the given advantages of this hybrid process, e.g., space-resolved and custom-designed roughness and the superior geometrical accuracy are evaluated. Finally, we exemplify the potential of this particular promising hybrid approach by demonstrating an injection mold with a conformal cooling for a charge socket for an electro mobile.

Studying Gas-Phase Flows in the Laser Exposure Zone during Selective Laser Melting

2020 ◽  
Vol 989 ◽  
pp. 806-810
Author(s):  
Pavel Anatolyevich Podrabinnik ◽  
C.E. Protasov ◽  
A.V. Gusarov
Keyword(s):  
Selective Laser Melting ◽  
High Speed ◽  
Ccd Camera ◽  
Opening Angle ◽  
Laser Exposure ◽  
Laser Melting ◽  
Schlieren Method ◽  
Outflow Velocity ◽  
All Optical ◽  
Powder Particles

The processes occurring during selective laser melting were studied with a high-speed CCD camera. In order to record all optical in-homogeneities, the camera was integrated into optical arrangement, that realized the Schlieren-method. Within the experiment three parameters were estimated, such as powder particles opening angle, their velocity and the outflow velocity of vapor-gas jet. The influence of laser setup parameters is given. It is shown that particle size and material composition, together with laser power, affect greatly on the opening angle and velocity of powder particles emission, respectively.

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