KR20010109311A - Method for manufacturing internal combustion engine pistons - Google Patents

Abstract

An internal combustion engine piston is manufactured by the piston manufacturing method according to the present invention. The piston manufacturing method includes the steps of forging a billet from an initial billet comprising an aluminum alloy comprising silicon, intermetallic particles, and injected cured particles under at least one of a superficiality and a high temperature strain condition, and heating the forged billet to a heat treatment . The forging step includes forging at a temperature in the range of about 0.8T _melt to about 0.98T _melt . The forging step also includes forging at a strain rate ranging from about 5 x 10 ^-2 s ^-1 to about 5 x 10 ^-5 s ^-1 . The piston is formed in such a manner that another portion can be connected to the piston. The starting billet comprises at least one of an assembly of silicon and intermetallic particles having at least one of a lamellar shape and a generic shape, and a group of fine silicon particles, intermetallic particles, and injected hard particles do. The volume content of silicon, intermetallic particles, and injected cured particles ranges from about 25% to about 60%, and the average crystal grain size of silicon, intermetallic particles, and injected cured particles is less than about 15 占 퐉 ² .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing an internal combustion engine piston,

Pistons are engine components that are typically subjected to high stresses. During piston operation, the top or crown of the piston may be exposed to high temperatures. Any groove formed in the piston, such as a groove for a compression ring, can be exposed to high impact stresses. Also, if the piston includes a piston pin port, the port may receive a reverse cyclic load. This piston contour will experience varying operating stresses, loads, temperatures and other operating characteristics (hereinafter referred to as " operating characteristics "), and different mechanical properties and mechanical qualities &Quot;). ≪ / RTI >

The mechanical properties of the piston can be determined by its characteristics. Pistons, such as but not limited to internal combustion engine pistons, typically include aluminum alloys. Such aluminum alloys include, but are not limited to, silumin, which can have a silicon content ranging from about 11% to about 35%. Also, if rumin piston chamber containing an alloy-based compound, the piston may further comprise a hardening agent (hardening agent), such as silicon carbide (SiC) and aluminum oxide (Al ₂ O _3). Silicon and intermetallic particles in the alloy may be combined with the curing agent to improve the heat resistance and abrasion resistance of the material. However, the resistance to metal fatigue and firing may be reduced as the heat resistance and the abrasion resistance are improved.

If the base material of the piston does not provide the desired properties, the stressed piston area can be formed from a material that can be cured. The curing may be carried out by incorporating at least one of an iron-based alloy and a ceramic material. For example, the piston portion may include an iron-holder, which is generally recognized as a heat-resistant material capable of reducing compression-groove wear. This piston portion can be reinforced by plasma-arc welding and spraying nickel, iron, and other reinforcing elements into the piston. The heat resistance of these materials protects the piston.

The shape and manufacture of the piston depends on the desired application of the piston. For example, a piston may be formed by casting as disclosed in an application entitled " Aluminum alloys in Tractor Building ", such as inventor Yu et al., In 1971 mechanical construction. This casting process provides a relatively efficient and low-cost manufacturing process, which enables the casting of a piston with a stiffener. Such reinforcements include, but are not limited to, piston ring holders, brackets, and the like. However, since aluminum-casting pistons are only exposed to low mechanical stress levels, such aluminum-casting pistons are generally used in low dynamic load (pressure) applications.

Another known piston manufacturing method is disclosed in U.S. Patent Application entitled " Isothermal Forging of Piston from an Alloy from an Alloy " by Yu et al. Includes hot deformed forgings from billets. This forging method is more expensive than the casting method, but the forged silamine-alloy piston provides improved mechanical properties. Thus, such silylmine-alloy pistons can be used in applications that are subjected to strong loads. Because of the low plasticity of the silylmin under high temperature deformation forging conditions, the forging process is usually carried out on a small and relatively simple piston. Therefore, a reinforcing material may be added to overcome such plastic defects, for example, by mounting a bracket on the piston. Such reinforcement complicates the shape of the piston and raises the manufacturing cost thereof. In addition, forging methods may be limited by forging temperatures that do not provide the desired amount and size for silicon and other hardened particles in the silumin-alloy. Therefore, known forging methods may not allow the silylmine-alloy piston to achieve the desired firing and mechanical properties. Therefore, there is a need for a piston manufacturing method capable of producing a piston having desired firing and mechanical properties. In addition, there is a need for a piston manufacturing method that overcomes the above-mentioned defects. Also, there is a need for a piston manufacturing method for a silylmine-alloy piston.

SUMMARY OF THE INVENTION

An internal combustion engine piston is manufactured by the piston manufacturing method according to the present invention. The piston manufacturing method includes the steps of forging a billet from an initial billet comprising an aluminum alloy comprising silicon, intermetallic particles, and injected cured particles under at least one of a superficiality and a high temperature strain condition, and heating the forged billet to a heat treatment . The forging step includes forging at a temperature in the range of about 0.8T _melt to about 0.98T _melt . The forging step also includes forging at a strain rate ranging from about 5 x 10 ^-2 s ^-1 to about 5 x 10 ^-5 s ^-1 . The piston is formed in such a manner that another portion can be connected to the piston. The initiation billet may comprise a coarse grain of silicon having at least one of a lamellar shape and a coarse shape, intermetallic particles, and silicon, intermetallic particles of a fine grain, And at least one of the group of hardened particles. The volume content of silicon, intermetallic particles, and injected cured particles ranges from about 25% to about 60%, and the average crystal grain size of silicon, intermetallic particles, and injected cured particles is less than about 15 占 퐉 ² .

Other aspects, advantages and salient features of the invention as well as others described above are set forth in the following detailed description that sets forth embodiments of the invention in connection with the accompanying drawings, Will become apparent from the description.

The present invention relates to the manufacture of internal combustion engine pistons for use in, for example, automotive engines, treaded or crawler-type machines, aircraft engines and engines of the marine system.

1 is a schematic view of a piston manufacturing system and method, wherein the left side of the axis is before the deformation occurs and the right side of the axis is after deformation;

Figure 2 is a schematic view of a piston in a ring holder manufacturing system in which the billet and ring holder are within the piston dies,

3 is a schematic view of the piston in the ring holder manufacturing system showing the forging of the piston crown on the left side of the axis and the forging of the piston inner side on the right side of the axis,

4 is a schematic view of a fused piston manufacturing system showing the left side of the axis is before deformation and the right side of the axis is after deformation,

5 is a schematic exploded view of a ring holder press working,

Figure 6 is a schematic view of a band-shaped piston with a ring holder,

Figure 7 is a schematic view of a cup-shaped inner case of a composite piston forged by a method embodying the invention,

Figure 8 is a schematic view of a cup-shaped outer piston case of a composite piston forged by a method embodying the invention,

9 is a schematic view showing the fitting of the inner case into the outer case,

10 is a schematic view of a composite piston after forging,

11 is a schematic view of a washer-shaped outer case and a cup-shaped inner case,

12 is a schematic view of a washer-shaped inner and outer case,

Figure 13 is a schematic view of a billet sandwiched by piston dies embodied by the present invention,

Figure 14 is a photograph of billets of various sizes produced by the piston manufacturing method practiced by the present invention,

15 is a photograph of a cross section of a piston having a bracket according to the present invention,

16 is a photograph of a silymin microstructure having silicon and intermetallic particles having a grain size of less than about 6 탆 ² ,

17 is a photograph of a silymin microstructure having silicon and intermetallic particles having a grain size of greater than about 15 mu m < ² >.

Pistons comprising silylmine alloys can be made with the piston manufacturing method and its associated system embodied by the present invention. A piston manufacturing method forms a piston by forging. Silvin-alloy pistons made by forging embodying the present invention contain various mechanical properties and properties within a single piston. These mechanical properties and properties are more dependent on the initial morphology and microstructure of the silylmine-alloy pistons. The mechanical properties and properties may also depend on the morphology and microstructure of the silylmine-alloy pistons produced by the deformation process in the piston manufacturing process embodying the present invention.

The piston manufacturing method practiced by the present invention is schematically illustrated by the piston die system of Fig. 1, the piston die system comprises a piston die matrix 1, a piston die 2, a pusher 3, a heater element 4, at least one liner plate 5 ), A billet (6) and a forged piston (7). Figure 2 also shows the features of the piston die system and the associated structure for the piston manufacturing method embodied by the present invention. 2 shows a ring holder 8, a spring 9, a piston die matrix guide 10, a piston billet 11 having a ring groove, a piston blank, a ring holder, a crown 12 and a ring holder 13 Fig. Figure 3 shows a fused material 14 molded by a piston manufacturing method practiced by the present invention.

Other features and associated structures of the piston die system are shown in other figures. These features include an alignment flange 15, a partially molded billet inner portion 16, a ring 17, a band-shaped ring holder 18, a cup-shaped billet outer case 19, A case 20, a washer-shaped outer billet case 21, and a washer-shaped inner billet case 22 are included.

The process for producing a silylimine-alloy piston according to the present invention can produce a silylmine-alloy piston by forging a fully formed piston having a structural reinforcement element (hereinafter referred to as "reinforcement"). The stiffener includes, but is not limited to, a ring holder and a piston bracket. The piston manufacturing method practiced by the present invention can be used for forming pistons of various sizes for internal combustion engines such as pistons used in automobiles, aircraft and marine products, and large road surface machinery. The piston manufacturing method can improve the piston manufacturing efficiency by providing the piston with mechanical properties and characteristics that meet the desired mechanical properties and characteristics of the intended application.

A method of manufacturing a piston embodying the present invention comprises forging a billet comprising an aluminum alloy composition. The aluminum alloy composition comprises at least one of silicon, intermetallic particles, and injected cured particles. Hereinafter, the aluminum alloy composition described above will be described, but other compositions may fall within the scope of the present invention. The particles may be provided in a lamellar form. For example, the composition for the initial billet, which is an aluminum alloy composition, also includes at least one of fine silicon, intermetallic particles, and injected cured particles. The injected cured particles can be generally spherical in shape.

After the forging step of the piston manufacturing method, a heat treatment step can be carried out. In the piston manufacturing method practiced by the present invention, the forging step can produce a piston comprising a large piston and a reinforcement. Also, the piston can be molded in such a way that the piston component can be easily connected to the piston by the piston manufacturing method. Forging step is carried out at about 0.8T to about 0.98T _melt temperature of the _melt range of the conventional piston material. The forging step of the piston manufacturing method is generally carried out at a strain rate ranging from about 5 x 10 ^-2 s ^-1 to 5 x 10 ^-5 s ^-1 .

The piston manufacturing method also includes forging steps performed under super plasticity or conventional high temperature deformation conditions. Wherein the average grain size of the silicon, intermetallic particles, and injected cured particles is less than about 15 占 퐉 ² and at least one of the silicon, intermetallic particles, and injected cured particles has an average grain size of about 25% Such conditions are generally provided provided that they have a volume content in the range of 60%. If the billet material composition includes particle content and particle size in excess of the above range, the forging may be carried out under high temperature deformation conditions. Thus, the larger the silicon or particle size, the lower the deformation rate can be provided. For example, forging can be performed at a strain rate ranging from about 10 ^-3 s ^-1 to about 5 × 10 ^-5 s ^-1 and a low forging temperature range, eg, from 0.83 T _melt to about 0.89 T _melt .

The billet material composition and shape properties can be considered when determining the piston manufacturing method parameters. For example, if the billet material composition comprises a grain weight content greater than about 20% and an average grain size greater than about 15 [mu] m < ^{2 &} gt ;, then the initial billet form and placement of the billet in the forging device may be considered for piston production. Such a billet material composition and shape characteristics can reduce the deformation that occurs in the manufacture of the piston implemented by the present invention. A piston manufacturing method that may include a forging step as described above may include a single step process. A piston manufacturing method including a single step process can be carried out under high temperature deformation and super plasticity conditions.

As a variant, the piston manufacturing process can be carried out at a strain rate in the range of about 0.90 T _melt to 0.98 T _melt temperature and also in the range of 5 10 ^-2 s ^-1 to 10 ^-3 s ^-1 . Such temperature and strain rate ranges are used in a piston manufacturing process using a billet material composition comprising at least one of silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than 6 占 퐉 ² . In the method of manufacturing a billet of such a billet material composition, the billet may undergo a primary deformation before the forging step. The primary strain may occur at strain rates ranging from about 0.79 T _melt to about 0.86 T _melt temperature and from about 5 x 10 ^-4 s ^-1 to about 5 x 10 ^-3 s ^-1 .

As a variant, the piston manufacturing method embodied by the present invention is characterized in that at least one of an average grain size of silicon, or intermetallic particles, having a particle size in the range of about 6 탆 ² to about 15 탆 ² , To form a piston from a billet comprising a billet material composition having a < RTI ID = 0.0 > Million parts per million (ppm) of such billet material composition is carried out at a strain rate ranging from about 0.84 T _melt to about 0.96 T _melt temperature and from about 10 ^-3 s ^-1 to about 5 x 10 ^-4 s ^-1 High temperature deformation forging.

Another variant of the piston manufacturing method according to the present invention comprises at least one of silicon, intermetallic particles and injected cured particles having an average crystal grain size of less than about 15 占 퐉 ² , The piston can be formed from a billet having a spherical shape. In this aspect of the piston manufacturing method practiced by the present invention, the volume percentage of silicon particles, intermetallic particles, and injected cured particles is in the range of about 25% to about 60%. With such a billet material composition, the piston manufacturing method may be carried out under super plastic conditions at a strain rate in the range of from about 0.88 T _melt to about 0.98 T _melt temperature and from about 5 x 10 ^-5 s ^-1 to about 1 x 10 ^-1 s ^-1 Includes forging performed.

The piston manufacturing method may also form a piston from a billet having a billet material composition comprising at least one of silicon, intermetallic particles, and injected cured particles in a volume less than about 15% of the total billet volume. This piston manufacturing method embodied by the present invention can use a billet material that can generally be provided with a tapered conical shape. The billet which can be a cast includes a billet material composition in which the contact of the billet and the piston die matrix is achieved only by the side, i. E. About 30% or more of its area.

In the piston manufacturing method, a gap distance may occur between the lower butt end of the billet and the base of the piston die matrix. The gap distance can be determined by the shape of the billet material. For example, the gap distance may be determined for the particle size and content of at least one of the silicon particles, intermetallic particles, and curing particles. This gap distance generally satisfies the equation h = dK / C /? F. (Unit: volume%) of at least one of silicon, intermetallic particles, and injected cured particles, and F is a silicon particle, a metal (Unit: mu m < ² >) of at least one of the solid particles, the intergranular particles, and the injected cured particles, K is the shape and size of the forged piston die-bit, and is generally in the range of about 0.5 to about 10.0 Lt; / RTI > Therefore, a billet containing an average grain size of less than about 15 占 퐉 ^{2 of} silicon, intermetallic particles, and injected cured particles, is essentially any strain at a constant temperature that is essentially the same as quenching temperature. Any instant quench cooling after the deformation process can complete the piston manufacturing process.

If the billet comprises silicon, intermetallic particles having a mean crystal grain size of less than 15 占 퐉 ² , and intercalated particles and less than 15% silicon particles, intermetallic particles and injected cured particles, From an alloy comprising silicon, intermetallic particles, and injected cured particles having a volume percent to volume percent and a particle size of 20 占 퐉 ² . In addition, the ring holder in the piston manufacturing method practiced by the present invention can be mounted in abutment with the butt end of the surface of the piston die matrix on the piston side with an interference fit. Thus, any hot deforming forging can be performed and the piston crown can be formed first and then the inner portion can be formed.

The piston manufacturing method practiced by the present invention may be used in a billet material composition comprising silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than about 15 占 퐉 ² and a volume ranging from about 25% to about 60% . In this combination, ring holders containing silicon, intermetallic, and injected cured particles having an average crystal grain size of less than 20 占 퐉 ² and a volume in the range of about 20% to 45% may be used. If the ring holder is mounted in an interference fit on the piston side and is placed in contact with the butt end of the piston, the forging step can be carried out under superplastic conditions. Therefore, the piston inner portion can be formed after the piston crown is formed.

A billet containing silicon, intermetallic particles having an average crystal grain size of less than 15 占 퐉 ² , and silicon, intermetallic particles, and injected hardened particles containing less than about 15% of the injected hardened particles, Or a ring holder made from steel may be used. The ring holder can also be mounted in a piston made of such a billet on the piston side and in contact with the butt end of the piston die matrix in an interference fit. The forging step of any piston in the piston manufacturing method practiced by the present invention can be carried out under super plasticity conditions. Therefore, the piston crown can be formed first, and then the inner portion of the piston is formed.

A billet containing silicon, intermetallic particles having an average crystal grain size of less than 15 占 퐉 ² and silicon, intermetallic particles and injected hardened particles comprising between about 25% and about 60% and containing injected cured particles, Or a ring holder made of steel may be used. The ring holder can also be mounted in a piston of this type of billet on the side with interference fit and also on the side of the piston die matrix and also on the butt end. Any forging step of the piston in the piston manufacturing method practiced by the present invention may be carried out under super plasticity conditions. Therefore, the piston crown is first formed and then the inner portion of the piston is formed.

According to another aspect of the present invention, an aligned surface in the shape of a cone of the ring holder and the piston body billet can be provided. The conical shape may include an angle ranging from about 1 [deg.] To about 10 [deg.]. The body billet may be made of a ring shoulder with a negative angle ranging from about 1 [deg.] To about 3 [deg.]. The ring holder may be positioned in the ring shoulder in an interference fit in the range of about 0.1 mm to about 0.2 mm in the radial direction. The positioning of the ring holder in the piston manufacturing method practiced by the present invention is generally performed at room temperature.

The piston manufacturing method including forging can be performed in two steps. First, the forging step includes positioning the ring holder into the piston die matrix. The positioning step can be performed by providing interference fit between the outer surface of the ring holder and the inner surface of the piston die matrix. The interference fit can be calculated as follows.

1.0017? D / D? 1.0035

Where d is the ring holder outer diameter at the forging temperature and D is the piston die matrix inner diameter at the forging temperature. Forging can be carried out by physically moving the piston die matrix in the forging direction and during subsequent piston crown forging the ring holder is fixed.

The ring holder in the piston manufacturing method practiced by the present invention may be coated with a layer of an aluminum containing alloy. The coating and the piston case may be made in essentially the same composition.

By the piston manufacturing method practiced by the present invention, two billets are used for forging a piston having an inner and an outer case. In a manner that does not limit the present invention, for example, a billet in a piston manufacturing process may comprise about 15% (total) silicon, intermetallic particles, and injected cured particles. Such a billet may be used to make the piston outer case. Another exemplary billet material composition includes about 15% (total) silicon, intermetallic particles, and injected cured particles. Such a billet material composition may be used to make the piston inner case, and the outer case may be mounted in an interference fit with the side surface of the piston.

A piston manufacturing method involving forging of two billets may use a billet having an exemplary billet material composition with silicon, intermetallic particles, and injected cured particles at about 45 vol.% To about 60 vol.% (Total). Such a billet material composition can be used to make the piston outer case. Exemplary billet material compositions comprising from about 25% to 40% by volume (total) of silicon, intermetallic particles, and injected cured particles can be used to make the piston inner body. During forging of such a piston, the piston die may be heated to a temperature which, for example, improves the deformation of the inner billet under super plasticity conditions. The piston die matrix may be heated to a temperature that enhances the deformation of the outer billet under super plasticity conditions. Further, such a piston manufacturing method can use a billet which is generally in a washer shape. As a variant, a piston manufacturing method involving forging of two billets may use a cup-shaped billet whose outer cup-shaped billets are tapered by the butt of the billet. In a piston manufacturing method involving forging of two billets, the inner cup is pressed into the outer cup to complete the assembly of the composite billet embodied by the present invention.

The billet in the piston manufacturing method according to the present invention may have protrusions, shoulders, or other extensions. The surface of the shoulder may comprise a wavy surface having a wave period L (see Fig. 6). The wave period L increases due to the billet material composition with silicon, intermetallic crystal grain size, and an increase in the injected cured particles. For example, the piston manufacturing method embodied by the present invention may further employ a steel washer, a spacer, or other separating device. The spacer may be positioned on the surface of the shoulder. The thickness of the washer generally satisfies the following conditions.

L / l = 4 to 42

In addition, the relationship between the height of the billet and the shoulder can be determined such that upon completion of the forging, the washer of the wavy shape is on substantially the same level as the compression ring groove of the piston.

A billet having silicon, intermetallic particles, and hardening the injected particles having a small average crystal grain size of less than about ² 15㎛ be located in contact with the bracket in the piston die matrix, and the bracket is a reflection of the surface of the billet. This orientation results in a lock joint that is formed after the piston is forged, e.g., using high temperature deformation. The bracket surface area S created in the constrained joint can be determined by the following equation.

S = KP / Sin? F

Where P is the separation force required to overcome the dynamic force generated during motor operation, K is the reliability coefficient, F is the aluminum alloy flow resistance at the working temperature, And the angle between the shoulder and the piston moving direction.

As an alternative, a total of silicon, intermetallic particles, and injected cured particles having silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than about 15 占 퐉 ² and ranging from about 25% to about 60% Billets containing volume content may be located in the piston die matrix during the piston manufacturing method as practiced by the present invention. This arrangement includes an arrangement for the bracket that reflects the surface of the billet. This arrangement results in constrained joints formed after the piston is forged under superplastic conditions. The bracket surface area S can be determined by the following equation as described above.

S = KP / Sin? F

As another variant, there is provided a process for preparing silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than about 15 占 퐉 ² , wherein the silicon, intermetallic particles, A billet containing the total volume content of the particles may be placed in contact with the bracket within the piston die matrix. The bracket may be formed of a porous ceramic material, such as a porous ceramic material, which is permeated into the aluminum alloy. The porosity of the porous ceramic material ranges from about 35% to about 50%. Therefore, the forging step in the piston manufacturing method practiced by the present invention can be carried out under super plasticity conditions. The same aluminum alloy composition as used in the manufacture of the piston case may be used for the infiltration of the porous ceramic material.

After the forging step, the piston formed by the piston manufacturing method practiced by the present invention may be further deformed. For example, the further modification is about 10 ^-2 s ^-1 to about 10 ^-4 s ^-1 in a strain rate range of from about 0.5 minutes to closed for about 5 minutes, the range of time from within the end (close-end) piston . For a billet material composition comprising silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than about 15 占 퐉 ² , the cured layer may be deposited on the piston surface. In this case, the high temperature deformation forging can be carried out at a temperature of from about 0.9T to about 0.96T _{melt melt} also range from about 5 × 10 ^-2 s ^-1 to about 10 ^-3 s ^-1 strain rate range.

The piston manufacturing method practiced by the present invention can improve forging conditions in the manufacture of a piston. This improvement can be implemented by considering the initial microstructure and chemical composition of the billet. Experiments show that the desired forging temperature interval can be provided to develop the desired mechanical properties. Forging of a billet having a complicated shape and large size can be accomplished at the above-described temperature and strain rate ranges while implementing the deposition technique of a billet in a piston dummy carried out by the present invention.

Pistons, such as simple shaped pistons, which are not cured or have stiffener elements added, may be used in low-rated organs. Such a piston can be manufactured from a billet by mold casting in another piston manufacturing method practiced by the present invention. Such a piston manufacturing method can produce a piston at a relatively low manufacturing cost. Casting is the cheapest method in billet manufacturing. The source material for mold casting may comprise an assembled microstructure comprising silicon, intermetallic grains having an average grain size of less than about 15 mu m < ² >.

For example, silylmines containing such microstructures typically exhibit low levels of firing under high temperature strain conditions. The silumin can also exhibit also high baked at about 10 ^-3 s ^-1 to strain rate of about 5 × 10 ^-5 s ^-1 at a temperature range of from about 0.86T to about 0.91T _{melt melt} range. Silvin of fine grain with particles having an average grain size of less than about 6 탆 ² can show high plasticity and can be used in the production of complex shaped and large shaped pistons. If the piston manufacturing method comprises pre-forged billets having such a microstructure, continuous casting and hot deforming forging may be provided, for example, by a pressing step. Increase in strain temperature range is possible due to reduction of alloy particle size. The temperature and strain rate at which deformation forging in the piston manufacturing process is carried out can affect the mechanical properties of the silyline material. The properties thus influenced can be recognized after the forging step of the subsequent piston manufacturing method and then any subsequent heat treatment steps are performed.

A piston manufacturing method practiced by the present invention produces a piston from a fine microstructure alloy. Fine-grained microstructure alloy _melt is about 0.9T to about 0.96T _melt temperature range and about 5 × 10 ^-2 s ^-1 to about 1 Mechanical properties after the desired strain in the × 10 ^-2 s ^-1 strain rate range of Can be developed. This property formed in the above-mentioned range is due to the formation of silicon, intermetallic particles in the billet material, and micropore in the vicinity of the injected hardened particles. The micropores can be formed under high temperature deformation conditions of the piston manufacturing process. The micropore size can be increased due to the reduction in strain rate applied during the piston manufacturing process. This reduction can be attributed to the mechanical properties obtained at the high strain rates imposed by the present invention.

In contrast, the piston manufacturing method can produce a piston from an assembled microstructure alloy. It has been determined that the assembled micro-tissue alloy can develop the desired mechanical properties after deformation at strain rates ranging from about 10 ^-3 s ^-1 to about 5 x 10 ^-5 s ^-1 . Further, the average crystal grain size of the deformation conditions for the billet material composition comprises from about ² to about 6㎛ 15㎛ ² range of silicon, intermetallic particles particles, and hardening the injected was also determined. Such deformation conditions include a temperature in the range of about 0.84 T _melt to 0.96 T _melt and a strain at a strain rate in the range of about 10 ^-3 s ^-1 to about 5 x 10 ^-5 s ^-1 .

The fine alloy in a piston manufacturing process comprising silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than about 6 탆 ² in the billet can be produced by high temperature transformation of the cast billet, The billet includes an assembled layered microstructure. The piston manufacturing process conditions for such deformation forging of silicon and intermetallic particles are from about 0.79 T _melt to about 0.96 T _melt and from about 5 x 10 ^-4 s ^-1 to about 5 x 10 ^-3 s ^-1 Strain rate.

The piston production method practiced by the present invention can be used to produce pistons containing various compositions, microstructures and crystal grain sizes under super plasticity conditions. In a non-limiting manner, for example, a piston comprising eutectic silumin reinforced with a brittle material, such as cured particles, may be produced by a piston manufacturing method practiced by the present invention . As a variant, a low stress-flow material hardened piston comprising a complex shape and reducing the ring holder deformation and the displacement relative to the piston itself can be formed by the piston manufacturing method embodied by the present invention. As another variant, a large piston which is stamped with a low pressure press can be formed by the piston manufacturing method.

The superplastic deformation conditions for the piston manufacturing method practiced by the present invention may also be used as silicon, intermetallic particles, and injected cured particles comprising an average crystal grain size of less than about 15 mu m < ² >. The superplastic deformation conditions also include silicon, intermetallic particles, and injected cured particles in the range of between about 25% and about 60% by volume. A strain rate in the range of about 5 x 10 ^-5 s ^-1 to about 5 x 10 ^-3 s ^-1 and a strain temperature in the range of about 0.88 T _melt to about 0.98 T _melt are the superplastic strain conditions for the above- Can be used.

The piston manufacturing method practiced by the present invention can forge a billet containing greater than about 15 weight percent silicon, intermetallic particles, and injected cured particles (both having an average crystal grain size greater than about 15 microns ² ) . Such a billet material composition usually exhibits a low level of firing. During the piston manufacturing process, the contact between the piston billet and the surface of the piston die matrix must occur within about 30% to about 100% of the sidewall surface area until the piston die-bit contacts the butt end. Such contact must prevent at least one of growth and formation in the billet of cracks.

In addition, the piston manufacturing method should provide the maximum distance between the billet base and the piston die matrix base. The distance generally depends, but is not limited to, the amount and size of the billet material, the size and shape of the silicon, the intermetallic particles, and the injected hardened particles, the billet diameter, and the size and shape of the piston die . A shorter distance between the base of the piston billet and the piston die matrix may be provided if the billet material composition is susceptible to brittle. This distance is required to prevent twisting of the billet when the piston die bit is disposed in the piston die matrix.

The piston manufacturing method practiced by the present invention may include quenching cooling after the forging is completed if the piston is forged at essentially the same temperature as quenching. Since the heating for the quenching step will be redundant, this procedure reduces the time of the piston manufacturing method and can be omitted accordingly. In addition, since there is no heating for quenching, crystal growth can be prevented when solidifying the aluminum of the billet material composition. This procedure may also provide a finer microstructure to the final piston.

The ring groove in the piston can be reinforced in the piston manufacturing method to limit the disintegration of the piston ring groove during engine operation. The ring grooves can be reinforced with metal ring holders, which generally provide strength at operating temperatures greater than the operating temperature of the billet material. For example, if the piston is formed as a casting, the ring holder may comprise cast iron reinforced by a coating, which is usually formed of a molten metal. As a variant, if the piston is forged, the ring holder may comprise microstructures comprising silicon, intermetallic particles, and an assembled silylmin with injected cured particles, since the silylmin typically has the strength properties laid down over the piston billet material can do.

For example, a fine grain silica or intermediate material having an average crystal grain size of less than about 15 탆 ² and containing less than about 15% by volume of silicon, intermetallic particles, and injected cured particles may be used as the piston Can be used in the production method. These materials can exhibit forging firing and the ring holder is formed from silylmine. Silumin comprises about 20% to about 45% silicon, intermetallic particles, and injected cured particles, wherein the silicon, intermetallic particles, and injected cured particles have an average crystal grain size greater than about 20 占 퐉 ² .

The ring holder may be located on the billet and may be positioned with the billet into the piston die matrix. An interference fit can be established between the piston billet surface and the butt end side of the piston die matrix to prevent the blank from cracking. The piston crown can be formed first so that the ring holder can be placed on the billet and avoiding deformation. The stress on the billet material during any high temperature deformation processing is typically less than the stress applied to the reinforcing ring holder material. Thus, the reinforcing material will fill the space around the ring holder, and the ring holder will normally undergo a minimum deformation less than about 20%. A piston billet having an " microduplex structure ", which means a billet comprising a billet material composition having a volume content of particles in the range of about 25% to about 60%, is produced by a piston manufacture Experience the method. In this piston manufacturing method, forging is performed with a press and the ring holder experiences less deformation.

A ring holder including silicon, intermetallic particles, and injected hardened particles containing at least one of iron and steel and having an average crystal grain size of less than about 15 占 퐉 ² prevents the repositioning of the ring holder and avoids ring holder deformation or fracture Can be used as a piston manufacturing method. To achieve this prevention, the ring holder may be inserted into the piston die matrix in an interference fit on the side surface and also abutting against the butt end surface. The piston crown is first forged and then the piston inner portion is formed under super plastic condition, which simplifies forging.

A reliable joint must be formed between the ring holder and the piston in the piston manufacturing method practiced by the present invention. Such a joint can be created by a piston material filling the ring holder cavity and then a joint deformation occurs. For example, if the oxide film is provided on the ring holder by pretreatment, removal of the film occurs when the ring holder is placed on the piston blank. The mating surfaces of the ring holder and the piston blank may be conical in shape with cone angles ranging from about 1 [deg.] To about 10 [deg.]. The piston and billet ring shoulder may include an engraved area ranging from about 1 [deg.] To about 3 [deg.]. The ring holder can also be pressed to a temperature in the range of about 15 [deg.] C to about 540 [deg.] C and also in the radial direction with a forced fit in the range of about 0.1 mm to 0.2 mm. The forging conditions embodied by the present invention can provide a reliable diffusion joint between the ring holder and the piston. The engraved surface prevents the mating surfaces of the butt end of the ring holder and the piston billet from being oxidized during heating and forging. A closed cavity can then be formed due to the different shape between the lower end of the ring holder and the ring shoulder. In addition, such a surface is prevented from contacting the furnace atmosphere, which can lower the oxidation rate of the piston billet and the ring holder during forging.

Further, due to the shape difference, deformation in the base of the ring holder and the shoulder may occur during forging. The deformation can reduce the oxide film and also promote the formation of a diffusion bond between the ring holder base and the shoulder surface.

Forging of a piston having a ring holder can be carried out by a two-step piston manufacturing method. First, the billet can be placed in contact with the butt end of the piston die with its ring groove region disposed upwards. The piston die stamps the piston crown and then the ring holder is pressed. Thereafter, the piston blank is conducted so that the crown faces downward, and the formation of the inside of the piston as the second stage of piston production is started.

The ring holder can be positioned within the piston die matrix and interference fit is formed between the ring holder outer surface and the inner surface of the piston die. This arrangement can prevent the ring holder from cracking while the piston undergoes the high temperature deformation treatment. This arrangement also prevents distortion caused by variations in the metal flow rate upon formation of the piston inner side. The interference fit characteristic can be calculated as the following equation.

1.0017? D / D? 1.0035

Where d is the ring groove outer diameter at the forging temperature and D is the piston die matrix inner diameter at the forging temperature.

If the interference fit is smaller than desired, cracking and torsion of the ring holder may occur. Tight fitting of the ring holder in the piston die matrix may make it difficult to insert the piston billet. If the piston manufacturing method includes positioning the ring holder on a billet of a cylindrical shape with little or no gaps therebetween, the piston die matrix will provide improved ring holder stability during the piston manufacturing process practiced by the present invention . This orientation can also prevent uneven metal distribution above and below the ring holder. This orientation combined with the ring holder position during forging can provide a stable platform for the ring holder.

Aluminum may be diffusion coated on the ring holder. A diffusion coating at high temperature can provide aluminum, such as a man aluminum alloy, that penetrates the ring holder of the steel. This procedure may remove the oxide film from the surface of the aluminum alloy piston and ring holder. In order to improve the reliability of the piston case and ring holder joints, any alloys used in the piston manufacturing method, for example coating, embodied by the present invention should have similar coefficients, even if they are not identical to the coefficient of linear expansion.

The two-layer piston configuration and the piston manufacturing method used to form such a two-layer piston configuration can provide reliable piston performance during initial startup of the engine. The two-layer piston shape can also provide improved reliability when the engine becomes hot and stressed. Silicon, intermetallic particles, and a two-layer piston shape with a high content of injected hardened particles can provide the desired strength properties at operating temperatures. However, at low temperatures, such as when the engine is first started, the materials used for the two-layer piston form may provide low levels of firing. However, silicon, intermetallic particles, and two-layered piston forms that include alloys in which the injected hardened particle content is low and have high firing levels, can provide fatigue resistance.

During engine start-up and warming, the two-layer piston configuration can transfer the piston pin force to the piston inner portion. The piston inner portion may be formed from an alloy comprising low silicon, intermetallic particles, and injected cured particles. The engine having a piston formed by the piston manufacturing method practiced by the present invention can achieve a temperature in the ring groove region in operation ranging from about 250 ° C to about 350 ° C and can be higher when subjected to maximum stress. The piston outer case alloy prevents the piston base from destroying the piston ring groove and prevents the piston base from disappearing at high temperature operating temperatures. A high content of silicon, intermetallic particles, and injected hardened particles ≪ / RTI >

Variations in piston thickness can be determined to improve piston manufacturing method characteristics, piston wear resistance, and firing. For example, the operating temperature during operation of the engine about the underside of the piston may be lower than the temperature in the ring groove area. During cold start of the engine, the lower edge of the piston skirt may receive impact stress as the piston moves from top dead center to bottom dead center. Because of this stress, the lower edge of the piston skirt should contain a material with high plasticity and sufficient abrasion resistance. This characteristic can be provided by minimizing the piston outer body thickness. If the firing is sufficient for forging, the shape of the piston billet may be a washer-like shape as described above since the shape is suitable for forging. On the contrary, if alloy firing is insufficient for forging or press working, the piston billet can be cup-shaped.

By assembling the composite piston billet before forging, removal of the oxide film coating the inner and outer case contact points can be facilitated. Removal can be performed by pressing the inner case into the outer case. An exemplary forging step to provide diffusion bonding may include providing a wave shaped piston billet. The billet shape may be provided by a low weight piston and a reinforced ring holder. The ring holder stiffener blank may also include a thin washer located on the undulating shaped piston billet butt end. After the first forging, these washers also take a wave shape. During forging of the piston crown, molten metal from the piston billet can be supplied between the washers. The molten metal can fill any space between the washers. Further, in the forging of blanks containing silicon, intermetallic particles, and injected hardened particles having an average crystal grain size of about 15 mu m < ² >, a gap having an interval of l / l = A gap free joint (l) may appear. Gapless joints can be created in the ring holder by forging the blank with silicon, intermetallic particles, and injected cured particles of average grain size having an average grain size of greater than about 15 탆 ² . The gapless lap (1) includes an interval determined by the formula l / l = 15 to 42.

As described above, the piston manufacturing method using the washer may include cutting the groove in the washer to receive the compression ring. The compression ring is in physical contact with the ring groove and can reduce the ring groove wear rate. The weight of the ring holder and the home wear rate can be improved by the stiffener washer.

The piston manufacturing method may also include attaching a bracket formed of a heat resistant material to the piston case. The attachment step includes, but is not limited to, any suitable means such as attachment by bolts. Since this bolting step can be time-consuming and expensive, the piston manufacturing method embodying the present invention can include attaching the bracket to the piston. The bracket can be formed as an integral plunger and can be attached to the piston without bolts. The formed mechanical joint can be created due to the flange surface area and its orientation to the forces of action generated during engine operation. The joints should be sufficient to hold the bracket and the piston case together as they can overcome inertia in the engine. By injecting the forged piston material into the bracket cavity in the piston manufacturing method practiced by the present invention, superplastic deformation conditions including the above-described bar can be provided.

The bracket may include a porous ceramic material that can be fused with an aluminum alloy to reduce weight. The ceramic material may include porosity having a porosity value ranging from about 35% to about 50% to provide frame strength. By fusing the ceramic material frame with the aluminum alloy and then bonding the aluminum layer to the surface, the piston case can be formed. This bonding step may result in a diffusion joint between the post-strain bracket and the piston case. If the fusing material and the piston case both have the same composition, the difference in linear expansion coefficient is eliminated, so that the formed joint reliability can be improved. Closing exposed to compression from all of the surface-applied for a further deformation of about 10 ^-5 s ^-1 to about 10 ^-4 s ^-1 of about 0.5 minutes to about 5 minutes under a strain rate range of time in the range of from-end piston die . This time removes the micropores, which leads to improved mechanical properties in the piston.

Wear in the ring groove can be attributed to a reduction in the strength of the piston alloy. This reduction is due to exposure to high temperatures during the piston manufacturing process. An increase in the material strength in the ring groove region can be provided by plasma welding. Plasma welding involves dissolving the material in the ring groove region by a plasma arc. After such plasma welding, alloy elements can be injected into the solution. However, this material dissolution step and the properties thereof are essentially the same as for the high temperature deformation and casting piston. When the fusion step is used for the piston billet and not used in the piston case, there may be a difference between them.

The fusing material may feature large iron or nickel-based intermetallic plates and shrinkage holes. Deformation of the fused material can be performed while the piston is forging. The modified fusion material may have a high level of hardness and the highest strength, which remains the same after heating to a temperature of about 250 < 0 > C. Since intermetallic fragmentation can occur during high temperature deformation processing, any of the improved features in the material can be attributed to dispersed microstructure. Also, the improved feature is not limited to, but not limited to, stress points such as shrinkage. If there is no shrinkage ball there may be an increase in the material's maximum strength, because the absence of shrinkage balls may increase the plasticity of the material.

A series of embodiments of a piston manufacturing method falling within the scope of the present invention will be described. The following operational steps for the piston manufacturing method embodying the present invention should not be construed as limiting the invention and merely provide guidance for steps falling within the scope of the present invention. The values set forth below are approximate and not to be construed as accurate.

The piston blank and the piston die may be pre-heated. Any modification is performed under isothermal conditions. The forging temperature is selected according to the initial microstructure and shape of the piston blank. The shape of the billet may depend on the average crystal grain size of the billet material composition and the silicon, intermetallic particles, and injected cured particles therein. Followed by quenching and artificial aging as a subsequent heat treatment step for the piston manufacturing process.

Example 1.

The cylindrical piston billet comprises a rough alloy composition of 12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% Ni, 0.4% Mn, 0.8% Fe and the balance Al. The billet was cut from a stock bar. This bar was produced by hot pressing the ingot at a strain rate of 90% s ^-1 at 440 ° C or 0.86 T _melt . The T _melt for the alloy corresponds to 552 캜 and was selected from the state diagram for Al and Mg systems. The resulting microstructure of the billet comprises spherical silicon and intermetallic grains having an average grain size of about 5 mu m < ² >. The billet was deformed at a strain rate of 1 x 10 ^-2 s ^-1 at 520 ° C (0.96 T _melt ) in a piston die system as shown in FIG. Quench cooling was carried out in water at 20 캜 after the deformation treatment. The aging was carried out at 210 DEG C for 10 hours. Microstructural analysis of the material showed no defects such as microcracks and micropores. The material had mechanical properties of sigma _b = 390 MPa.

Example 2.

Piston billets of an alloy composition comprising 21% Si, 1.6% Cu, 1.1% Mg, 0.1% Ti, 1.1% Ni, 0.5% Mn, 0.7% Fe and the balance Al were prepared by block mold casting. The average crystal grain size of silicon and intermetallic particles is about 120 탆 ² and is in the form of a layer. The billet was tapered into a conical shape at an angle of 4 DEG. The billet size is such that 50% of the surface area is brought into contact with the piston die matrix when fitted into a piston die matrix having an inner diameter of 150 mm and a conical angle of 4 degrees. The distance from the lower butt end of the billet to the butt end below the piston die matrix can be determined by the equation H = dK / C√F. Here, d = 150, K = 5, C = 21, F = 120. The distance was calculated to be 3.2 mm. The billet was deformed at an average strain rate of ⁴占 폚 (0.91 T _melt ) and 1 占 10-4 s ^-1 in a piston die system (see FIG. 1). The heat treatment sequence included quenching at 510 DEG C and aging at 210 DEG C for 10 hours. To which other pistons were determined to be inherently defect free. Another test showed that σ _b = 250 MPa.

Example 3.

The billet was forged from a cylindrical blank in the piston die system of Fig. 1 at a temperature of 520 캜 (0.96 T _melt ) and a strain rate of 1 x 10 ^-2 s ^-1 . The blank was cut from the pressed ingot. Press-forming temperature is about 440 ℃ to about 450 ℃ (about 0.86T to about 0.88T _{melt melt)} range to the deformation (strain) of 90%. The ingot composition contained 12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 0.4% Mn, 0.8% Fe, and the balance Al and contained an average grain size of silicon and intermetallic particles of about 6 μm ² did. A mechanical treatment on the head of the conical surface of the billet with the ring shoulder was performed to form a cone angle of about 6 degrees and a sound opinion angle of about 3 degrees. A ring holder with a flat lower butt end was formed from an aluminum alloy having a silicon content of about 18%. The ring holder was pressed into the head of the billet using a ring in contact with the shoulder at 20 ° C.

In this series of the above-described steps, a closed cavity is formed between the flat butt end of the ring holder and the ring shoulder of the billet. The billet has a press ring holder and can be heated to a temperature of 510 ° C in the furnace. The billet was fitted into the piston die system simultaneously with the pressing of the ring holder and the formation of the piston combustion chamber. Forging was carried out at isothermal conditions at a strain rate of 10 ^-3 s ^-1 using a hydraulic press at 510 ° C (0.95 T _melt ). After forging the ring holder, the piston was quenched in water and aged at 210 ° C for 10 hours. The strength test indicated that the joint between the piston body and the ring holder was 140 MPa.

Example 4.

A piston blank comprising an aluminum alloy having a composition comprising 12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% Ni, 0.4% Mn, 0.8% Fe, and the balance Al is used in the piston manufacturing process . The alloy contained an average crystal grain size of silicon and intermetallic particles at 5 μm ² and the crystal was spherical. An alignment protrusion was formed on the piston, and a cast iron ring holder was provided so as to be in contact with the projection. The cast iron ring holder was installed by pressing the ring holder into the projection. Prior to installation on the billet, the ring holder was coated with a layer of molten aluminum alloy that essentially contained the same composition as the billet. The billet with the ring holder was fitted into the piston die matrix with forced fit. Forging was carried out at an average strain rate of 10 < ^-3 > s < ^-1 > under high temperature strain conditions at 490 DEG C (0.93 T _melt ). A piston crown was first formed (see left in FIG. 2), and then an inner portion of the piston (see right in FIG. 2) was formed. Subsequently, the forging step, quenching and artificial aging were carried out.

In this embodiment, the aluminum alloy may be coated on the holder. After cooling, the aluminum alloy coating fused to the ring groove surface. As the ring holder is pressed into the piston billet, the oxide film coating from both the piston billet and the ring holder surface has been removed. The high temperatures and deformations that occur during forging provide conditions for the generation of permanent fusion joints. The strength of such a joint is usually sufficient to prevent subsequent heat treatment and deployment of a gap between the piston body and the ring holder during actual use.

Example 5.

12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 0.4% Mn, 8% Fe, and the remainder including Al and the aluminum alloy billet, further comprising an average grain size of between silicon and metal particles in 12㎛ ² Was used. This billet was formed as an integral sole. The butt end surrounding the shoulder was a wave shape as described above. The ring holder was manufactured from wave shaped sheet steel with a thickness of 3 mm. The billet and ring holder wave periods were calculated using the formula L = l (4-14). Here, 1 is the thickness of the thin plate on which the ring holder is manufactured, for example, 3 mm. In using the above equations, L is in the range of about 12 mm to about 42 mm. In the experiment, L was 30 mm. The ring holder was fixed to the blank and positioned in the piston die matrix. The piston was then forged. Subsequent heat treatment included quenching and artificial aging.

Example 6.

A composite piston comprising two cases, namely an inner and an outer case, was used. The outer case billet included 21% Si, 1.6% Cu, 1.1% Mg, 0.1% Ni, 0.5% Mn, 0.7% Fe, and an aluminum alloy with the balance Al. The billet also contained silicon and intermetallic grains having an average grain size of 30 mu m < ^{2 &} gt ;. The inner case billet is a spherical shape having an average crystal grain size of 5 탆 ² and containing 12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% Ni, 0.4% Mn, 0.8% Fe, It was formed from an alloy having silicon and intermetallic particles. The outer and inner case billets were washer shaped. The piston was forged by simultaneous forging of the two billets at a strain rate of 10 ^-3 s ^-1 at 490 ° C (0.93 T _melt ). Subsequent heat treatment sequences included quenching and artificial aging.

Example 7.

The piston billet body was made from an aluminum alloy having a composition of 12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% Ni, 0.4% Mn, 0.8% Fe, and balance Al. The aluminum alloy piston blanks included an alloy having a composition of 21% Si, 1.6% Cu, 1.1% Mg, 0.1% Ti, 0.5% Mn, 0.7% Fe, and balance Al. The alloy contained an average crystal grain size of silicon and intermetallic particles of 120 μm ² . A bracket made of 40% porous silica mullite was fused with an aluminum alloy having the same composition as the piston billet. The inner bracket surface was coated with an aluminum alloy layer and had a thickness of 2 mm. The brackets and billets were fitted into a piston die piston dies matrix and heated to 480 ° C (0.91 T _melt ). The strain was performed at a strain rate of 10 ^-4 s ^-1 . After forging, quenching cooling was carried out in the atmosphere. The aging was carried out at 350 DEG C for 8 hours. The connection between the piston and the bracket was determined to be reliable and permanent.

Example 8.

The blank cut from the hot pressed aluminum alloy rod was formed with a composition of 12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% Ni, 0.4% Mn, 0.8% Fe, and balance Al. The alloy contained spherical silicon and intermetallic particles with an average grain size of 6 탆 ² . At a distance of 20 mm from the end, the piston ring section was melted and sprayed with a nickel-chromium solvent, such as nickel-chromium wire. Dissolution was carried out in a three or three operation in an argon atmosphere using a solid electrode. The first stage included a nickel-chromium solvent feed rate of 65m / hour and a welding speed of 41m / hour. In the second and third steps, the welding was carried out without injection of the alloy element and the welding speed was 25 m / hour. The current during this step was in the range of about 680A to 700A and the voltage was 220V. The melting depth was 7 mm.

Billets having a dissolution layer with a nickel content of 7% and a chromium content of 2% were heated to 470 캜 (0.9T _melt ) in the furnace. The billet was then placed in a piston die piston die matrix mounted under the hydraulic press.

Billets, splices, and dissolved layer deformation were performed at a strain rate of 10 < ^-3 > s < ^{-1 &} gt ;. The forging was carried out under isothermal conditions and the blank and piston die temperatures were about 470 ° C and the average strain rate was 10 ^-3 s ^-1 . The piston was removed from the piston die with the aid of a pusher. Quenching was carried out in water at a temperature of 510 ± 10 ° C. The aging was carried out at a temperature of 210 캜 for 10 hours. Ring grooves were formed during the final machining process of the piston. No microcracks or micropores were found.

While various embodiments have been described herein, it will be appreciated by those skilled in the art that combinations, modifications, or improvements of various elements may be made to those skilled in the art, and these are within the scope of the present invention.

Claims (30)

A piston manufacturing method for manufacturing an internal combustion engine piston, A method for forging a billet produced from an initial billet comprising silicon, intermetallic particles, and an aluminum alloy comprising injected cured particles, said forging being carried out under at least one of a superficiality and a high temperature strain condition, Heat treating the forged billet, The forging step is from about 0.8T to about 0.98T, and _melt comprises a _melt forging at a temperature in the range, the forging step is also deformation of about 5 × 10 ^-2 s ^-1 to about 5 × 10 ^-5 s ^-1 range Wherein the piston is formed in a shape such that the other portion can be connected to the piston, The initiation billet A group of assembled silicon, intermetallic particles, and injected hardened particles having at least one of a lamellar shape and a comprehensive shape, A group of fine spherical silicon particles, intermetallic particles, and injected hard particles, Wherein the volume content of silicon, intermetallic, and sprayed hardened particles is in the range of about 25% to about 60%, and the average crystal grain size of the silicon, intermetallic, and sprayed hardened particles is less than about 15 탆 ² A method of manufacturing a piston. The method according to claim 1, A low strain rate in the range of about 10 ^-3 s ^-1 to about 5 x 10 ^-5 s ^-1 , a temperature in the range of about 0.83 to 0.89 T _melt , a particle content of more than 20%, an average crystal grain size of 15 μm ² Bigger A method of manufacturing a piston. The method according to claim 1, Wherein the starting billet comprises silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than about 6 占 퐉 ² and wherein the forging step has a temperature in the range of about 0.90T _melt to 0.98T _melt, ^-2 s ^-1 to about 10 ^-3 s ^-1, which contains the high temperature deformation forging that runs on the strain rate in the range A method of manufacturing a piston. The method of claim 3, Wherein the method further comprises deformation at a temperature in the range of about 0.79 T _melt to 0.96 T _melt and at a strain rate in the range of about 5 x 10 ^-4 s ^-1 to about 5 x 10 ^-3 s ^-1 A method of manufacturing a piston. The method according to claim 1, 6㎛ about ² to a temperature of about ² 15㎛ range from about 0.84T to about 0.96T _{melt melt} range with respect to the silicon, billets comprising an average grain size of the intermetallic particles, and hardening the injected particles and about 10 ^-3 s ^{- 1} to about 5 x 10 < ^-4 > s < ^-1 > A method of manufacturing a piston. The method according to claim 1, The average crystal grain size is less than about 15㎛ ² silicon, intermetallic particles, and includes a jet hardening particles with spherical shape, and the silicon, intermetallic particles, and the injection of a volume content of cured particles of about 25% to about 60% of a _melt temperature of from about 0.88T to about 0.98T _melt range under superplastic conditions with respect to the billet and about 5 × 10 ^-5 s ^-1 to about 1 × 10 ^-1 s ^-1 strain rate range to be forged is running on A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises a tapered conical shape and the contact of the billet and the piston die matrix is contact at a side surface and the contact is at least 30 percent of its area, Lt; RTI ID = 0.0 >% < / RTI > A method of manufacturing a piston. 8. The method of claim 7, d is the inner diameter (unit: mm) of the bottom of the piston dies matrix, C is the content of silicon, intermetallic particles and injected cured particles (unit: vol%), F is silicon, intermetallic particles, Wherein the distance between the lower butt end and the piston die matrix base is an average area of the hardened particles (unit: 占 퐉 ² ) and K is a coefficient related to the shape and size of the upper die in the range of about 0.5 to about 10, dK / C√F A method of manufacturing a piston. The method according to claim 1, Wherein the deformation is carried out at the same temperature as the quench temperature and quench cooling occurs after deformation of the billet comprising silicon, intermetallic particles, and injected hardened particles having an average crystal grain size of less than about 15 mu m < ² & A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than 15 占 퐉 ² and comprising less than about 15% silicon, intermetallic particles, and injected cured particles, A ring holder comprising silicon, intermetallic particles, and an alloy comprising injected cured particles having a particle size of greater than about 20 占 퐉 ^{2 in the} range of from about 40% to about 40% by weight, said ring holder comprising a piston die matrix Mounted on the surface in an interference fit A method of manufacturing a piston. The method according to claim 1, The billet comprises silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than 15 占 퐉 ² and silicon, intermetallic particles, and silicon, intermetallic particles and injected hardened particles having a volume in the range of about 25% to about 60% Wherein the holder has an average crystal grain size of less than 20 < RTI ID = 0.0 > ² < / RTI > ² and comprises silicon particles, intermetallics and injected cured particles in the range of about 20% A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises silicon, intermetallic particles, and injected hardened particles having an average crystal grain size of less than 15 mu m < ² > and less than 15% silicon, intermetallic and injected hardened particles, The ring holder being provided in the piston A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than 15 占 퐉 ² and wherein the volume of silicon, intermetallic particles, and injected cured particles is in the range of about 25% to about 60% A ring holder including cast iron or steel is provided on the piston A method of manufacturing a piston. 13. The method of claim 12, Forming an aligned surface of the ring holder and the body billet of the piston in a conical shape with an angle between about 1 [deg.] And about 10 [deg.], And forming a ring shoulder at an engraved angle between about 1 [ Wherein the ring holder is located within the ring shoulder in a radial direction with an interference fit in the range of about 0.1 mm to about 0.2 mm and the ring holder is placed at ambient temperature A method of manufacturing a piston. 13. The method of claim 12, Wherein said forging step comprises two steps A method of manufacturing a piston. 13. The method of claim 12, Wherein the arrangement of the ring holders in the piston die matrix comprises providing an interference fit between the ring holder outer surface and the inner surface of the piston die matrix wherein d is the ring holder outer diameter at the forging temperature and D is Wherein said interference fit is calculated by the equation 1.0017 < d / D < / = 1.0035, and said forging step comprises, when forming a piston crown, said piston die matrix in the forging direction, And < RTI ID = 0.0 > physically < A method of manufacturing a piston. 13. The method of claim 12, Further comprising coating the ring holder with an aluminum alloy A method of manufacturing a piston. 17. The method of claim 16, Providing the piston casing with the coating formed of the same alloy A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises 15% silicon, intermetallic particles, and injected cured particles, wherein the method comprises providing two billets for forging the piston, wherein the billet is used to make a pass tone inner case And the outer body is mounted on the side surface in an interference fit A method of manufacturing a piston. The method according to claim 1, Piston forging includes forging from two billets, one of which includes silicon, intermetallic particles, and injected cured particles in the range of from about 45% by volume to about 60% by volume for making the piston outer case And the other billet comprises 40% silicon, intermetallic particles, and injected cured particles in the range of from about 25% by volume to about 40% by volume for making the piston inner case, Heated to a temperature for deformation under A method of manufacturing a piston. 20. The method of claim 19, When the billet is in a washer- A method of manufacturing a piston. 20. The method of claim 19, The billet is cup-shaped and the outer cup is tapered to the butt end A method of manufacturing a piston. 22. The method of claim 21, Further comprising the step of pressing the inner cup into the outer cup to form a composite billet A method of manufacturing a piston. The method according to claim 1, Characterized in that the billet comprises a wave-like projection with a wave period (L), a steel washer is disposed on the surface, the washer has a thickness satisfying the condition L / l = 4 to 42, The relationship is determined such that the washer is on the same level as the ring groove when the forging is completed A method of manufacturing a piston. The method according to claim 1, Wherein the billet is positioned in the piston die matrix in contact with a bracket containing silicon, intermetallic particles and injected hardened particles having an average crystal grain size of less than 15 [mu] m < ² > and reflecting the surface of the billet, K is the reliability coefficient, F is the aluminum alloy flow resistance at the operating temperature, and alpha is the flow resistance of the projection and piston < RTI ID = 0.0 > When the angle between the directions of motion is such that the bracket surface area S can be determined by the equation S = KP / Sin? F A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than 15 占 퐉 ² and having a volume of silicon, intermetallic particles, and injected hardened particles in the range of about 25% to about 60% The billet is placed in the piston die matrix in contact with the bracket that reflects the surface of the billet to form a restraint after the piston has been forged from the aluminum alloy under super plastic conditions and P is required to overcome the forces generated during engine operation K is the reliability coefficient, F is the aluminum alloy flow stress at the operating temperature, and? Is the angle between the plane of the projection and the piston motion direction, the surface area S of the bracket satisfies the equation S = KP / Sin? F Which can be determined by A method of manufacturing a piston. The method according to claim 1, Wherein the billet comprises silicon, intermetallic particles, and injected cured particles having an average crystal grain size of less than 15 占 퐉 ² and having a volume of silicon, intermetallic particles, and injected hardened particles in the range of about 25% to about 60% Wherein the billet is positioned in contact with a bracket made of a porous ceramic material infiltrated with an aluminum alloy in a piston die matrix and wherein the porosity of the ceramic frame is in the range of about 35% to about 50% and the forging is carried out under super plasticity conditions A method of manufacturing a piston. 27. The method of claim 26, The same aluminum alloy is used for the ceramic frame and the piston case A method of manufacturing a piston. The method according to claim 1, The piston is closed-end end of the piston is less than about 10 ^-5 to about 10 ^-4 s ^-1 is received more a variation for a time of about 5 minutes to about 0.5 minutes at a strain rate in the range A method of manufacturing a piston. The method according to claim 1, Forming a step, and a cured layer to provide a billet in which the method comprises silicon, intermetallic particles, and hardening the injected particles having a smaller average grain size than 15㎛ ² to the piston surface, from about 0.9T _melt To about 0.96 T _melt and a strain rate ranging from about 5 x 10 < ^-2 > to about 10 < ^-3 > s < ^{-1 &} A method of manufacturing a piston.