Ferrous-WC Composite Analysis

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.