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Si3N4/Al–Mg composites based on Al–Mg alloy reinforced by ceramic interpenetrating network structure were fabricated via pressureless infiltration technology. Infiltration temperature and infiltration time are the key parameters distinctly effecting on infiltration processes. Moreover, the increasing of Mg content (2–8 wt.%) resulted in an increased amount of infiltration. Microstructural characterization of the composites reveals a special topology of skeleton and good integrity of metal/ceramic interface. The presence of second reinforced phase results in a significant increase in 0.2% offset yield and ultimate tensile strength of composites materials. However, when the volume fraction of reinforcement is large than 6%, there are a distinctly reduction of strength. The presence of additional secondary brittle phase in matrix results in the reduction in ductility and increase in hardness of 3-DNRMMCs. The failure features as cracking and void in reinforcement, interface cracking and interface debonding as well as matrix damage result in the decreases of fracture toughness. With the increases of volume fraction of reinforcement, 3-DRMMC exhibits excellent wear-resistance property.Si3N4/Al–Mg composites based on Al–Mg alloy reinforced by ceramic interpenetrating network structure were fabricated via pressureless infiltration technology. Infiltration temperature and infiltration time are the key parameters distinctly effecting on infiltration processes. Moreover, the increasing of Mg content (2–8 wt.%) resulted in an increased amount of infiltration. Microstructural characterization of the composites reveals a special topology of skeleton and good integrity of metal/ceramic interface. The presence of second reinforced phase results in a significant increase in 0.2% offset yield and ultimate tensile strength of composites materials. However, when the volume fraction of reinforcement is large than 6%, there are a distinctly reduction of strength. The presence of additional secondary brittle phase in matrix results in the reduction in ductility and increase in hardness of 3-DNRMMCs. The failure features as cracking and void in reinforcement, interface cracking and interface debonding as well as matrix damage result in the decreases of fracture toughness. With the increases of volume fraction of reinforcement, 3-DRMMC exhibits excellent wear-resistance property.

In this paper we investigate the problem of estimating thed-dimensional probability densityf(x),x?Rd from a sample of sizen. The non-parametric estimator is the data based histogramfn(x) as defined in (1). Under suitable conditions, we have proved theL1-norm consistance of this estimate, that is $$\mathop {\lim }\limits_{n \to \infty } \int_{R^a } {|f(x) - f_n (x)|dx = 0,{\text{ a}}{\text{.s}}{\text{.}}}$$

Magnesium calcium alloy has attracted more and more attention in the medical metal field as it has the similar mechanical properties with human bone and biodegradable property. In this paper, the preparation and modification of the alloy were studied. It was found that, extrusion parameters had an important impact on the quality of product in extrusion process, like extrusion ratio, extrusion temperature and extrusion speed. Vickers hardness, and tensile mechanical properties test and bending mechanical properties were carried on as-cast and extruded alloy to obtain mechanical parameters, the mechanical property of MgCa0.8 alloy greatly improved after extrusion, and the extrusion process can be applied to other calcium content alloys.