Particles Reinforced Iron Matrix Composites Research Articles

Microstructural evolution and performance analysis of WC-11Co reinforced iron matrix composites

This paper presents a new fabrication method utilizing lost foam casting as a processing technique to synthesize high-strength and ultra-wear-resistant particle reinforced iron matrix composites. The composite material incorporates large-sized WC-11Co reinforcement. The composite exhibits a multiphase microstructure composed of WC-11Co, α-Fe, and carbide precipitates that extend at different length scales. The precipitation of large-sized M3W3C (M = Fe, Co) type carbides at the WC-11Co/matrix interface is well controlled. A favorable reaction layer is formed between WC-11Co and the matrix. Nano-precipitates are pinned within the reaction layer, exhibiting a high degree of coherence with the iron matrix. The stress field at the interface is complex due to thermal stress, phase transformation stress, and microstress. The stress state between WC-11Co and the matrix consists of compressive residual stress-tensile residual stress-compressive residual stress, with compressive residual stress far exceeding tensile residual stress. The WC-11Co/Fe0.35C5CrMn composite exhibits outstanding compressive strength of 2.18 GPa and a fracture strain of approximately 24.6 %. Moreover, the composite demonstrates excellent wear resistance, with a threefold improvement compared to the matrix under severe wear conditions. The following mechanisms contribute to the enhanced mechanical properties: multiphase material system, coherent multiscale interfaces, grain refinement, dislocation strengthening, and residual stress strengthening.

WC-18Co reinforced Iron matrix composites: Microstructure and interface characteristics

Particle reinforced iron matrix composites have gained considerable attention as advanced structural materials. In this study, large-sized WC-18Co reinforced iron matrix composites were prepared using the casting infiltration method. We investigated the microstructure and interface characteristics of WC-18Co/FMC, analyzed the stress state at the interface, and tested the mechanical and tribological properties of the composite material. The research findings reveal that WC-18Co/FMC is a multiphase system composed of WC, M3W3C (M = Fe, Co), and precipitates. The strong interface reaction results in the formation of a thick transition layer between WC-18Co and the matrix. Grain refinement occurs around the reinforcing particles. During solidification, the difference in thermal expansion coefficients between WC-18Co and FMC induces thermal stress, leading to compressive residual stress on both sides of the interface. The compressive stress state inhibits crack initiation and propagation, enhancing the bonding strength. Alternating stresses at the interface enhance dislocation motion, grain slip, and twinning phenomena in the transition layer. Nanoscale compounds embedded in the transition layer impede dislocation slip, resulting in dislocation entanglement and pile-up. WC-18Co/FMC exhibits a 60.66% increase in hardness compared to FMC. Under impact energies of 1 J, 3 J, and 5 J, the wear resistance improves by factors of 2.985, 2.358, and 2.072, respectively. The significant improvement in the composite material's performance is attributed to strengthening mechanisms such as the multiphase system, grain refinement, nanoscale precipitates, and residual stress strengthening.

Research and prospect of particle reinforced iron matrix composites

Research and prospect of particle reinforced iron matrix composites

Interfacial bonding and abrasive wear behaviours of the iron matrix composites

Ceramic particles reinforced iron matrix composites attract considerable interest in the industrial engineering field due to the ceramic’s excellent fatigue and wear resistance. ZTA ceramic particle has been regarded as an ideal reinforcement phase. In this study, three-body abrasive wear behaviours and the mechanism of the ZTA/Fe composites and high chromium white cast iron Cr15 standard samples were investigated. The wear resistance of the ZTA/Fe composite was superior to the Cr15 standard sample under SiO2 abrasives. The extruded ZTA could protect the matrix surrounding ZTA ceramic particles. However, ZTA ceramic particles were cut together with the Cr15 matrix under SiC abrasives. The wear mechanism of the composites was a combination of the cutting and fatigue for SiC abrasives.

Effects of manganese on diffusion and wear behavior of ZTA particles reinforced iron matrix composites in vacuum

Different volume fraction ZTA particles reinforced high chromium cast iron (HCCI) matrix composites were fabricated by liquid phase sintering (LPS) in vacuum of −0.1 atmospheric pressure. The influence of manganese on the microstructure, phase constituents and mechanical properties of the ZTA particles reinforced HCCI composites was investigated by means of SEM, XRD, and nanoindentation tests. The results demonstrated that the interfacial layer with a thickness of 25–35 μm was formed between ZTA particles and HCCI matrix, combined the effects of manganese additions. The elements in the interfaces layer are mainly Mn, Si, Zr and Al with a small amount of Fe. New phases formed by MnO acting on the surface of ZTA particles and the interfaces were MnO2·Al2O3, Mn2SiO4 and MnFe2O4. However, in the interfaces layer near the matrix, MnO was reduced by C to form Mn and Mn3C and dissolved in HCCI matrix. The hardness and modulus of the interfacial layer were 20.25 GPa and 294.7 GPa, respectively. The wear mass losses of Cr20 sample is about 4.7 times higher than that of 40 vol% ZTA particles reinforced iron matrix composites.

Simulation of stress distribution and evolution in SiC particle reinforced iron matrix composites

An Eshelby particle-compounded model was employed to investigate the stress distribution in the SiCp/Fe composites during straining in order to predict the stress-strain curves of the composites. Effect of the SiC volume content and aspect ratios on yield strength of the SiCp/Fe composites was studied by the simulation. The modeling results indicate that the stress in the iron matrix is much smaller than that in SiC particles as straining the composites, which means the strengthening mechanisms of the SiCp/Fe composites is determined by the load transfer mechanisms. The aspect ratios of the particles play a significant role in yield strength of the SiCp/Fe composites especially as the particle volume content is large. The stress in SiC particles has a stronger dependence on the aspect ratios of the particles only if the reinforcement volume content is small.

Wettability and interaction mechanism for Ni-modified ZTA particles reinforced iron matrix composites

The wetting behaviors of bare and Ni-modified zirconia toughened alumina (ZTA) with molten iron matrix have been explored by sessile drop technique and gathered to compare their wettability. Experimental results show that the wetting angles of molten 65Mn steel and high chromium cast iron (HCCI) matrix on bare ZTA substrates are 104.1° and 102.3°, respectively, whereas it is decreased to 83.6° and 88.2° on Ni-modified ZTA substrates. The wetting angle of HCCI matrix on Ni plate is just 1.5° in 1 min. At high casting temperature, element Ni originated from Ni coating can diffuse into molten Fe and keep constant basically. Small amount of element Ni can react with Al2O3 on ZTA/Fe interface to form Al2NiO4. A schematic illustration of the cast-infiltration process is put forward, which indicates that Ni-modified ZTA can be wetted with molten iron through Ni diffusion and reactive wetting. A ZTA/Al2NiO4/Fe interface layer is formed by mechanical bonding, interdiffusion and small amount of chemical reactions, to achieve composites with tight interfacial bonding strength. Besides, Ni-modified ZTA particles are prepared through electroless plating assisted with Ethaline additive and used as precursor to reinforce 65Mn steel matrix composite by nonpressure casting infiltration method.

Dry sliding wear investigation on tungsten carbide particles reinforced iron matrix composites

WC particles reinforced Fe-based metal matrix composites were synthesized by powder metallurgy process. The microstructure and composition of the specimens were analyzed and the wear-resistant properties against WC and alumina balls were comparatively investigated by SEM/EDS analyses. The wear rates of specimens were evaluated by optical profilometry. Microstructure exhibited austenite Fe-FCC dendrites, eutectic (iron austenite + carbides) and primary carbides. Two wear mechanisms have been identified from SEM as main mechanisms during dry sliding wear of Tungsten carbides reinforced iron matrix, namely oxidation and abrasion. The overall wear performance, which is obtained by considering the wear loss of the substrates, indicated less resistance against Alumina compared to WC ball contact.

The Particle Shape of WC Governing the Fracture Mechanism of Particle Reinforced Iron Matrix Composites.

In this work, tungsten carbide particles (WCp, spherical and irregular particles)-reinforced iron matrix composites were manufactured utilizing a liquid sintering technique. The mechanical properties and the fracture mechanism of WCp/iron matrix composites were investigated theoretically and experimentally. The crack schematic diagram and fracture simulation diagram of WCp/iron matrix composites were summarized, indicating that the micro-crack was initiated both from the interface for spherical and irregular WCp/iron matrix composites. However, irregular WCp had a tendency to form spherical WCp. The micro-cracks then expanded to a wide macro-crack at the interface, leading to a final failure of the composites. In comparison with the spherical WCp, the irregular WCp were prone to break due to the stress concentration resulting in being prone to generating brittle cracking. The study on the fracture mechanisms of WCp/iron matrix composites might provide a theoretical guidance for the design and engineering application of particle reinforced composites.

Preparation of nickel coating on ZTA particles by electroless plating

With the aim to effectively improve the interface between ZrO2 toughened Al2O3 (ZTA) particles and metal matrix, nickel was deposited on the surface of ZTA particles by electroless plating method. Formation mechanism of nickel coating and effects of the solution pH, loading capacity of ZTA particles and temperature on the nickel deposition were investigated. Microstructures, thickness and element distributions of nickel coating were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results showed that the nickel was successfully deposited on the surface of ZTA particles by electroless plating without noticeable defects. The process of electroless nickel plating could be explained by combination of atomic hydrogen and electrochemistry theories. The interfacial nucleation of nickel is easier to form than spontaneous nucleation in the solution. Deposited Nickel has priority on the surface of ZTA particles comparing to that in solution. The optimal conditions to coat nickel on the surface of ZTA particles are: solution pH 4.7–4.8, loading capacity 15–20 g/L, and electroless plating temperature 85 °C. The ZTA particle reinforced iron matrix composites prepared by powder metallurgy could have better interfacial bonding between ZTA particle and iron matrix because of the nickel coating on the surface of ZTA particle. Nickel diffuses into the iron matrix during the sintering preparation of composite materials. The interface between ZTA particle and iron matrix presents the evidence of non-chemical bonding.

Characterization of interfacial layer of ZTA ceramic particles reinforced iron matrix composites

Experimental evidence is first provided for the reaction product in the interfacial layer of ZTA (zirconia toughened alumina) ceramic particles reinforced HCCI (high chromium cast iron). Phases formed in the interfacial layer during solidification were identified by TEM and HRTEM. It is confirmed that they were the amorphous Na4SiO4 phases. The diffusion of Al is faster than that of other elements in the interfacial layer. The hardness and modulus of interfacial layer were 1877.5 HV and 299.8 Gpa, respectively. The phase transformation (t-ZrO2→m-ZrO2 and θ-Al2O3→α-Al2O3) occurred during the composite preparation.

Effects of Different Matrix on Interface and Compression Fracture Behavior of WC Particles Reinforced Iron Matrix Composites

The WC particles reinforced iron matrix composites were prepared by utilizing energy ball milling powder mixed and vacuum powder sintering method in this paper. The effects of two kinds of matrix on the micro-structure, interface and fracture mechanism of the composites were studied emphatically, and it provided a theoretical guidance for the design and engineering application of particle reinforced metal matrix composites. The results show that: in the two kinds of matrix composites, WC particles and interface had different degree of melting, WC particles and the matrix were metallurgical combination; ferritic matrix composites had better compressibility than pearlite matrix composites (1089Mpa); the fracture mode of ferrite matrix composites was quasi-cleavage fracture and pearlite matrix composites was pure cleavage fracture; the compressive micro-cracks of the two matrix composites generated at the interface and expand at the interface to a broad macroscopic crack, which eventually the material fails.

Tribology characteristics of ex-situ and in-situ tungsten carbide particles reinforced iron matrix composites produced by spark plasma sintering

Abstract In this paper, ex-situ (adding the particles reinforcement phase into the matrix materials directly) and in-situ (the particles were synthesized directly from elemental powders of W and C during the fabrication) tungsten carbide particle reinforced iron matrix (WC/Fe) composites were well fabricated by spark plasma sintering (SPS) with the particle volume fraction of approximately 30%. The main phases were ferrite, WC, W2C, Fe3W3C and pearlite. The content of Fe3W3C in ex-situ WC/Fe composites was much higher than that in in-situ WC/Fe composites, and some of which spread throughout particles in ex-situ WC/Fe composites. The homogenous distribution of WC particles within the iron matrix was obtained with strong bonding to the matrix. The mean WC grain size was about 24 μm and 13 μm for ex-situ and in-situ WC/Fe composites, respectively. Compared with the traditional martensitic wear-resistant steels, these two type composites presented the more excellent wear resistance which was enhanced at least six times. Moreover, due to the better particles size and interfacial microstructure, the in-situ composite had the lower specific wear rate (2.5 × 10−5 mm3/Nm) which was about 65% to that of the ex-situ composite (3.8 × 10−5 mm3/Nm). The dominant wear mechanism for the in-situ and ex-situ WC/Fe composites was a combination of abrasive wear and oxidation wear, which was different from the micro-ploughing mechanism of the martensitic wear-resistant steel. For the ex-situ composites, coarse-grained WC and higher content of brittle phase Fe3W3C increased the wear rate and reduced the wear-resistance.

Formation mechanism and stability of the phase in the interface of tungsten carbide particles reinforced iron matrix composites: First principles calculations and experiments

Abstract

Effects of atmosphere on sintered properties of fibre and particle reinforced iron matrix composites: S.K. Mukherjee (University of Sydney, Sydney, Australia), Powder Metallurgy Science and Technology, Vol 3, No 4, 1992, 26–37

Effects of atmosphere on sintered properties of fibre and particle reinforced iron matrix composites: S.K. Mukherjee (University of Sydney, Sydney, Australia), Powder Metallurgy Science and Technology, Vol 3, No 4, 1992, 26–37