Investigation of the Effect of Tungsten Carbide (WC) Nanopowder on Iron-Based Powder Structural Materials

2021 ◽  
Vol 316 ◽  
pp. 455-460
Author(s):  
V.M. Gavrish ◽  
T.V. Chayka ◽  
G.A. Baranov

Studies of a powder used as a modifier obtained from solid-alloy waste, such as tungsten carbide (drill balls), are presented. Dispersion, particle morphology and phase analysis of the powder were studied. The powder obtained from solid-alloy waste is a phase – it is tungsten carbide WC, it consists of nanoobjects of various shapes (nanoparticles, nanoplastics) up to 100 nm in size, with a slight presence of agglomerates up to 250 nm in size. The influence of tungsten carbide nanopowder as a modifier on the mechanical properties (strength and hardness) of PK70D3 iron-based powder structural steel has been studied. For the study, two different modes of preparation of powder alloy have been used with the use of one-stage and two-stage sintering. The influence of additive nanopowder of tungsten carbide on the mechanical properties of structural alloy powder based on iron PK70D3 has been defined: strength increases by more than 23% (in single-stage sintering), by more than 28% (in double-sintering), hardness decreases by more than 6% in single-stage sintering and increases by more than 26% with two stages of sintering, compared to the initial alloy. It has been shown that samples, obtained using double sintering with a tungsten nanopowder modifier (2.5%), have higher values of strength (more than 80%) and hardness (more than 13%), compared to modified samples, obtained by single-stage sintering technology. Thus, the modification of a 2.5 % nanoprobe of tungsten carbide, a widely used structural powder alloy based on iron PC70D3 allows for a significant change in mechanical properties. The use of powder alloys in double sintering technology provides the material hardness and the strength increase.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud Haghighi ◽  
Hossein Golestanian ◽  
Farshid Aghadavoudi

Abstract In this paper, the effects of filler content and the use of hybrid nanofillers on agglomeration and nanocomposite mechanical properties such as elastic moduli, ultimate strength and elongation to failure are investigated experimentally. In addition, thermoset epoxy-based two-phase and hybrid nanocomposites are simulated using multiscale modeling techniques. First, molecular dynamics simulation is carried out at nanoscale considering the interphase. Next, finite element method and micromechanical modeling are used for micro and macro scale modeling of nanocomposites. Nanocomposite samples containing carbon nanotubes, graphene nanoplatelets, and hybrid nanofillers with different filler contents are prepared and are tested. Also, field emission scanning electron microscopy is used to take micrographs from samples’ fracture surfaces. The results indicate that in two-phase nanocomposites, elastic modulus and ultimate strength increase while nanocomposite elongation to failure decreases with reinforcement weight fraction. In addition, nanofiller agglomeration occurred at high nanofiller contents especially higher than 0.75 wt% in the two-phase nanocomposites. Nanofiller agglomeration was observed to be much lower in the hybrid nanocomposite samples. Therefore, using hybrid nanofillers delays/prevents agglomeration and improves mechanical properties of nanocomposite at the same total filler content.


2021 ◽  
Vol 56 (15) ◽  
pp. 9196-9208
Author(s):  
Piotr Borysiuk ◽  
Piotr Boruszewski ◽  
Radosław Auriga ◽  
Leszek Danecki ◽  
Alicja Auriga ◽  
...  

AbstractIn this study, wood plastic composites (WPC) made of poly(lactic acid) PLA and a bark-filler were manufactured. Two degrees of bark comminution (10–35 mesh and over 35 mesh) and varied content of bark (40, 50 and 60%) were investigated. The studied panels were compared with analogically manufactured HDPE boards. The manufacture of composites involved two stages: at first, WPC granules with the appropriate formulation were produced using the extruder (temperatures in individual extruder sections were 170–180 °C) and crushing using a hammer mill after cooling the extruded composite; secondly, the obtained granulate was used to produce boards with nominal dimensions of 300 × 300 × 2.5 mm3 by flat pressing in a mold, using a single daylight press at a temperature 200 °C. The study proved that comminuted bark can be applied as a filler in PLA composites. However, an increase in bark content decreased mechanical properties (MOR, MOE) and deteriorated humidity resistance (high TS and WA) of the panels. Along with the increase in bark content, an increase in the contact angle of the composite surfaces and a decrease in the total surface energy were noted. It was also found that PLA composites have higher strength parameters and lower moisture resistance compared to HDPE composites with the same bark content. Graphical abstract


Author(s):  
Lubomir Anestiev ◽  
Jordan Georgiev ◽  
Seryozha Valkanov ◽  
Marcela Selecká ◽  
Sabine Cherneva ◽  
...  

Abstract The influence of the carbon introduction method on the microstructure and the mechanical properties of sinters produced from iron-based powders by diffusion-alloying sintering has been studied. Two methods of carbon introduction were tested: (1) Premixing of the base powder with graphite, and (2) Coating of the base powder with a carbon-containing substance. The results obtained could be summarized as (1) The microstructure and the mechanical properties depend on the method of carbon introduction; (2) The sinters produced from coated powders possess finer micro-structure, improved homogeneity, and in two out of three of the studied compositions, better mechanical properties. Based on the results obtained, a reasonable assumption was made that the method of carbon introduction affects the dissolution rate of the carbon additive, thus affecting the micro-structure and the mechanical properties of the sinter.


Author(s):  
Teresa D. Golden ◽  
Jeerapan Tientong ◽  
Adel M.A. Mohamed

Electrodeposition of only molybdenum onto substrates is difficult, therefore molybdenum is typically deposited with iron-based alloys such as nickel. The deposition of such alloys is known as an induced codeposition mechanism. The electrodeposition of nickel-molybdenum alloys using alkaline plating solutions is covered in this chapter. The mechanism for deposition of nickel-molybdenum is reviewed, as well as the influence of the plating parameters on the coatings. Characterization of the coatings by scanning electron microscopy and x-ray diffraction is discussed and how deposition parameters affect morphology, composition, and crystallite size. Nickel-molybdenum alloys offer enhanced corrosion protection and mechanical properties as coatings onto various substrates. A survey of the resulting hardness and Young's modulus is presented for several research studies. Corrosion parameters for several studies are also compared and show the percentage of molybdenum in the coatings affects these values.


2020 ◽  
Vol 405 ◽  
pp. 379-384
Author(s):  
Joanna Borowiecka-Jamrozek ◽  
Jan Lachowski

The main purpose of this work was to determine the effect of the powder composition on the microstructure and properties of iron-based sinters used as a matrix in diamond tools. The Fe-Cu-Ni sinters obtained from a mixture of ground powders were used for experiments. The influence of manufacturing process parameters on the microstructure and mechanical properties of sinters was investigated. Sintering was performed using hot-pressing technique in a graphite mould. The investigations of obtained sinters included: density, hardness, static tensile test, X-ray diffraction analysis, microstructure and fracture surface observations. The obtained results indicate that the produced sinters have good plasticity and relatively high hardness.


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