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Questions and Answers
What is the role of W and C atoms in a ferrous–WC composite during the melting process?
How does increased scanning speed affect the densification of Fe–WC composites?
What is the effect of a weak interfacial connection in a ferrous-WC composite?
What is a result of having thicker interfacial layers in a ferrous-WC composite?
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What primary characteristic is influenced by the gradient interface in Fe-WC composites during laser AM?
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What happens to microstructural morphology when scanning speed is decreased?
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What factors can cause fluctuations in the size and shape of the interface gradient in a ferrous-WC composite?
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What effect does the faster cooling rate of LPBF have on TiB2 particles in 316–TiB2 composites?
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Which of the following contributes to boosting the wear resistance of a ferrous-WC composite?
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How does Marangoni convection influence TiB2 particle behavior in 316–TiB2 composites?
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What structural phases are present in laser-processed H13–TiB2 composites?
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What mechanism leads to strengthening phases during laser melting of H13–TiB2 composites?
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What is the effect of the laser's faster heating and cooling cycle on TiC structures?
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Which factor contributes to the spreading out of TiC particles during laser processing?
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What advantage is noted for ceramic-reinforced ferrous composites like WC?
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How does the melt's surface tension gradient affect TiB2 distribution in the matrix?
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What effect does higher composite hardness have on adhesive processes?
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How does the laser affect the behavior of vanadium carbides in the LPBF process?
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What happens to VCx phases during the solidification process?
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What is a significant factor in the rapid melt process of ultrafine vanadium carbide in the LPBF technique?
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During laser AM of Ti–TiC composites, how is density enhanced?
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What role does the particle size of VC play in the formation of ferrous–VC composites?
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What is a characteristic result of using the LPBF technique in creating ferrous–VC composites?
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How does the solidification speed of the laser AM process influence the diffusion of V and C in the austenite solid solution?
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Study Notes
Ferrous-WC Composite
- WC can maintain 1400°C room temperature hardness.
- Fe-based alloys are reinforced with ceramic components to improve wear properties.
- In Fe–WC composites, dissolved WC reinforcing components release W and C in the liquid melt.
- W and C atoms react with ferrous alloy to generate carbides near grain boundaries.
- A gradient interface MC3 (M = W, Fe, Cr, Ni) develops between WC reinforcing element and matrix during laser additive manufacturing (LAM) procedures.
- Gradient interfaces strengthen WC and Fe matrix bonds.
- Size and shape of the interface gradient fluctuate with laser power, intensity, and spot size.
Ferrous-WC Composite
- Ferrous-WC composite performance depends on densification, gradient interface, microstructural morphology, and hardness development.
- Lower scanning speeds increase densification, which improves wear.
- A weak interfacial connection between reinforcing components and matrix causes composite wear.
- Interfacial layers without pores and fissures ensure composite bonding.
- Thicker interfacial layers provide strong bonding, making it difficult to wear away WC components, improving wear property.
316 SS-TiB2 Composite
- In 316–TiB2 composites, reinforcing components form a ring-like structure.
- LPBF's faster cooling affects composites.
- Higher cooling rates (106 K/s) limit TiB2 grain growth, forming finer TiB2 particles.
- The temperature gradient in laser AM causes a melt’s surface tension gradient.
- Marangoni convection moves TiB2 particles by limiting accumulation and regulating distribution across the cemented matrix.
- 316 melts entirely, but TiB2 doesn’t.
- Marangoni forces move TiB2 elements.
- Matrix melting repels TiB2 particles.
- Repulsive force and Marangoni convection generate a TiB2 ring-like structure.
H13–TiB2 Composite
- Laser AM in tool production allows for the digital production of intricately formed parts.
- AM reduces the cost of tools, shortens production times, and reduces personnel through robotics.
- Laser-processed H13–TiB2 has -Fe and TiB2 phases, but no austenite.
- Faster heating and solidifying cycles stimulate fine equiaxed grains with uniform TiB2 reinforcement along H13 grain borders.
- During laser melting, when a full liquid forms, the dissolution mechanism generates strengthening phases by heterogeneous TiB2 nucleation and grain growth.
H13–TiC Composite
- The laser's faster heating and cooling cycle help TiC structures happen by shortening the time TiC grains need to grow.
- When the temperature goes up, the Marangoni flow gets stronger, and capillary forces push the liquid along.
- Shear and rotational forces that form around the TiC particles could help particles spread out evenly, preventing them from sticking together.
- Lower volumetric energy density can cause particles to stick together more.
Ferrous-WC Composite
- AM ceramic arenas are interested in MMCs strengthened with ceramic particles.
- Ceramic-reinforced ferrous composites perform better.
- WC has a high melting temperature and excellent wettability with many ferrous alloys.
- Higher composite hardness can hinder adhesive processes like scuffing and removing material, reducing wear rate and improving wear property.
Ferrous-VC Composites
- Through LPBF, vanadium carbides reinforce ferrous matrix composites..
- The laser’s energy and the pressure/flow in the laser-stimulated liquid melt pool disintegrate micron-sized VC through a melting-solidifying mechanism.
- The laser light rapidly heats the 316L/VC mixture, forming a molten region of entirely dissolved V8C7/316L liquids.
- V8C7 can quickly dissolve and release V and C due to tiny particle size, high surface tension, and laser heat.
- The tiny pressure on ultrafine VC in the liquid melt pool accelerates the rapid melt process.
Ferrous-VC Composites
- After the laser source leaves the melt, it solidifies quickly.
- During fast solidification, VC and VCx develop through heterogeneous nucleation and grain expansion of VC nuclei.
- The matured VCx strengthening components will be disseminated at grain boundaries and in the austenite grains due to nucleation and progression.
- When VCx phases become bulky, grain expansion pushes them toward grain boundaries.
- VCx phases are retained within austenite grains.
- As laser AM has a quick solidification process, few V and C diffuse into the austenite solid solution.
Ti–TiC Composite
- In laser-based additive manufacturing (AM) of Ti–TiC composites, different amounts of Ti and TiC powders are mixed and milled with a ball mill to get a better density.
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Description
This quiz focuses on the properties and performance factors of Ferrous-WC composites, including the effects of gradient interfaces and manufacturing techniques. Explore how these composites maintain hardness and improve wear resistance through densification and microstructural morphology during laser additive manufacturing.
