Composited cast member, iron-based porous substance for composited cast members, and pressure casing processes for producing the same, constituent member of compressors provided with composited cast members and the compressors

Abstract

A pressure casing includes a composited cast member. The composited cast member includes an iron-based porous substance whose major component is Fe and which has a large number of pores, and a cast-wrapping member whose major component is a light metal and which cast-wraps a part of the iron-based porous substance at least. The iron-based porous substance includes a connector disposed adjacent to a boundary between the iron-based porous substance and the cast-wrapping member and exhibiting a larger porosity, and a high-strength reinforcer disposed in the iron-based porous substance free from the connector and exhibiting a smaller porosity. The connector is impregnated with the cast-wrapping member, and solidifies therewith, thereby firmly bonding the iron-based porous substance and the cast-wrapping member in the composited cast member. The pressure casing secures strength with the reinforcer, and secures adhesiveness with the connector.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a composited cast member in which an iron-based porous substance is wrapped with a light alloy, an iron-based porous substance used in the composited cast member, a pressure casing provided with the composited cast member, processes for producing the same, a constituent member of compressors, an example of the composited cast member or pressure casing, and the compressors. [0003] 2. Description of the Related Art [0004] In view of weight saving, outputting higher power and recycling, raw materials for various component parts are changing from iron-based materials, such as iron, steels and cast steels, to light metallic materials, such as aluminum alloys and magnesium alloys. However, when such light alloy materials substitute for the entire component members, it is difficult to secure strength, rigidity, slidability, wear resistance and durability. Accordingly, composited cast produc...

AI Technical Summary

Benefits of technology

The present invention provides a composited cast member with an iron-based porous substance that demonstrates the reinforcement effect stably and securely while also securing firm adhesiveness between the iron-based porous substance and the cast-wrapping member. This is achieved by impregnating the iron-based porous substance with a molten metal for making a cast-wrapping member and solidifying it therewith. The invention also provides a process for producing the composited cast member.

Problems solved by technology

However, when such light alloy materials substitute for the entire component members, it is difficult to secure strength, rigidity, slidability, wear resistance and durability.

However, it cannot necessarily be said that the weight saving of cylinder blocks is fully achieved when sleeves made of cast steels are cast-wrapped by light metallic materials.

Moreover, in this instance, the adhesiveness is poor at the interface between cast-steel sleeves and cast-wrapping members composed of light metallic material, such as aluminum alloys, for example, and consequently the cast-steel sleeves and cast-wrapping members might be separated at the interface during the service as cylinder blocks.

When the porosity of iron-based porous substances is large, that is, when the volume fraction of iron (Vf) is less, such iron-based porous substances cannot demonstrate a sufficient reinforcement effect naturally.

Accordingly, the adhesiveness between iron-based porous substances and cast-wrapping members are likely to degrade.

Consequently, it is hardly possible to expect to strengthen composited cast members as a whole.

However, it is not preferable to add harmful Be.

As a result, although the resulting composited cast members can secure wear resistance as cylinder liners, it is hardly expected for the porous substances to produce the reinforcement effect as expected from composited cast members as a whole.

The use of composite materials is not suitable for mass-produced products which are required to be produced at low cost, because ceramic fibers, the reinforcement members, are expensive.

Moreover, component parts using composite materials exhibit poor processability, because ceramic fibers are very hard.

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