CN105642886A

CN105642886A - Powder metallurgical method

Info

Publication number: CN105642886A
Application number: CN201510795091.7A
Authority: CN
Inventors: 赵英喆; 金钟文; 郭滢锡
Original assignee: Hyundai Motor Co
Current assignee: Hyundai Motor Co
Priority date: 2014-11-27
Filing date: 2015-11-18
Publication date: 2016-06-08
Also published as: KR20160063868A; KR101664603B1; DE102015222656A1; JP2016102259A; US20160151838A1

Abstract

A powder metallurgical method includes preparing a liquid lubricant by mixing ethylene bis stearamide 60 to 70 wt % and erucamide 30 to 40 wt % at 150 to 170 DEG C. in a high temperature stirring process. A pulverized solid lubricant is prepared by cooling the liquid lubricant to form a solid and pulverizing the solid. A powder metallurgy composition is prepared by mixing the pulverized solid lubricant 0.4 to 0.75 part by weight to metal-based powder 100 parts by weight, and a molded body is prepared by compression molding of the powder metallurgy composition.

Description

Powder metallurgy process

Technical field

The present invention relates to a kind of powder metallurgy process. More specifically, it relates to a kind of powder metallurgy process, and the lubricant joining metal matrix powder can be reduced to minimum by it, and shaping energy and demoulding energy remain on level that is equal or that improve simultaneously.

Background technology

Owing to engine obtains superpower, the parts of vehicle startup machine and variator are it should be ensured that higher mechanical property. As the method improving these mechanical propertys, develop many forming techniques, but due to when under high pressure shaping the production cost of parts improve and to damage of mould etc., the application of these forming techniques is often restricted. , as guaranteeing highdensity mode under the pressure similar to existing general forming pressure (400��700MPa), there is the method for reducing lubricant addition in many highdensity forming techniques.

In field of powder metallurgy, it may also be useful to the object of lubricant is the internal friction, evenly the compressing powder metallurgy that reduce between metal matrix powder particle and damage minimumization making the mould on die press technology for forming. But, when compression molding contains the metal matrix powder of lubricant, lubricant is retained between metal matrix powder particle, thus can not obtain highdensity formed body. But, when reducing the amount joining lubricant in metal matrix powder, because the friction resistance between pressed powder and mold wall increases, there is burn failure such as the problem of die wear, and when pressed powder is from mould during the demoulding, knockout press increase. In addition, be there is restriction in the density improving pressed powder, because the lubricity in the metal matrix powder particle that compression molding is adjoint is reset between powder particle reduces.

On the other hand, as the method for hybrid lubricant and metal matrix powder, having 1) for the mechanically mixing method of simple hybrid lubricant, and 2) for being polymerized the polymerization process of the monomer as lubricant basal component.

Mechanically mixing method comprises the size that the basal component of lubricant is broken for 25 ��m or less, then adds the basal component of metal matrix powder and lubricant in a mixer, they is mixed subsequently, therefore there is the advantage that process is fairly simple. On the other hand, due to high demoulding energy, there is the shortcoming that the addition of lubricant can not reduce, and the low surface roughness guaranteeing formed body is disadvantageous by this.

Polymerization process comprises and adds in polymerization reactor by polymer solvent, adds the monomer for the manufacture of lubricant and metal matrix powder wherein, then heats them at 100 DEG C to be polymerized. This polymerization process causes the intermolecular chemical bonding of lubricant basal component. Therefore, it has the advantage guaranteeing homogeneity and low demoulding energy, but has and make due to the process of its complexity manufacturing cost increase too many shortcoming.

Now, in field of powder metallurgy, by making addition minimumization of lubricant, the urgent metallurgical method needing exploitation can obtain highdensity formed body and can maintain low demoulding energy after compression molding completes during the demoulding is.

In the above-mentioned information disclosed in background section only for strengthening the understanding of the background technology to the present invention, therefore it may comprise the information not being formed in national known prior art for those of ordinary skills.

Summary of the invention

It is devoted to herein to solve the problems referred to above relevant to prior art.

An object of present inventive concept is to provide the powder metallurgy process of a kind of improvement, knockout press and forming pressure, by the lubricant joining metal matrix powder is reduced to minimum, are remained on level that is equal or that improve to manufacture high-density formed body by the method simultaneously.

In order to achieve the above object, on the one hand, the present invention provides a kind of powder metallurgy process, and it comprises the following steps: prepare liquid lubricant by the erucicamide of the ethylene bis-stearamide and 30��40wt% that mix 60��70wt% in high-temperature stirring process at 150��170 DEG C; By cooling liqs lubricant to form solid and milled solid prepares powdery solid lubricant; Powder metallurgical composition is prepared by being mixed with the metal matrix powder of 100 weight parts by the powdery solid lubricant of 0.4��0.75 weight part; Formed body is prepared with by compression molding powder metallurgical composition.

In certain embodiments, described metal matrix powder can be iron-based powder.

In certain embodiments, described compression molding can carry out under the pressure of 500��600MPa.

In certain embodiments, from mould, formed body is deviate from by applying the knockout press of 900��1400Kgf.

In certain embodiments, the step preparing formed body also comprises the knockout press of applying 900��1100Kgf, and formed body has 7.2��7.3g/cm³Density, and compression molding carries out under the pressure of 500��600MPa.

Other side and the preferred implementation of the present invention are discussed hereinafter.

It is understandable that, " vehicle " or " vehicle " or other similar terms generally include Motor vehicles as comprised the passenger vehicle of SUV (Sport Utility Vehicle) (SUV), motorbus, truck, various commercial vehicle as the term is employed herein, comprise the ship of various canoe and boats and ships, aircraft etc., and comprise hybrid electric vehicle, power truck, plug-in hybrid electric vehicle, hydrogen-powered vehicle and other fuel substitute automobile (such as from the fuel that non-oil resource is derivative). As mentioned in this article, hybrid electric vehicle is the vehicle with two or more propulsion source, such as, be the vehicle that petrol power is also electric power.

Accompanying drawing explanation

Above and other feature of the present disclosure is described in detail by its now illustrated with reference to the accompanying drawings some illustrative embodiments, and accompanying drawing only provides below by way of illustration, does not therefore limit the disclosure, wherein:

Fig. 1 is according to the chart comparing knockout press as the ethylene bis-stearamide of lubricant composition and the change of erucicamide content ratio, preparing in powder metallurgy forming body with the use of the metal matrix powder of 100 weight parts and the lubricant of 0.75 weight part, described lubricant is prepared by high-temperature stirring process;

Fig. 2 is the chart comparing knockout press, in the process preparing powder metallurgy forming body with the use of the metal matrix powder of 100 weight parts and the lubricant of 0.75 weight part, wherein the ratio of components of ethylene bis-stearamide and erucicamide is 70:30wt%, described lubricant is prepared by high-temperature stirring process;

Fig. 3 is the chart that knockout press is compared in the change of the addition according to lubricant and forming pressure, in the process manufacturing powder metallurgy forming body with the use of the metal matrix powder of 100 weight parts and the lubricant of 0.4 weight part, wherein the ratio of components of ethylene bis-stearamide and erucicamide is 70:30wt%, and described lubricant is prepared by high-temperature stirring process;

Fig. 4 is according to the chart comparing knockout press as the change of the ethylene bis-stearamide of lubricant composition and the content ratio of erucicamide, preparing in powder metallurgy forming body according to conventional methods with the use of the metal matrix powder of 100 weight parts and the lubricant of 0.75 weight part, described lubricant is by the preparation of at room temperature mechanically mixing process;

Fig. 5 is according to the chart comparing knockout press as the ethylene bis-stearamide of lubricant composition and the change of erucicamide content ratio, in the process preparing powder metallurgy forming body with the use of the metal matrix powder of 100 weight parts and the lubricant of 0.75 weight part according to conventional methods, described lubricant is prepared by polymerization process; And

Should be understood that, appended accompanying drawing is not necessarily drawn in proportion, presents in certain degree of the various preferred features of the fundamental principle that the present invention is described the expression simplified. The specific design feature of the present invention as disclosed herein comprises such as concrete size, direction, position and shape, will partly determine by specific expection application and environment for use.

In the accompanying drawings, the reference number in several figure of whole accompanying drawing refers to identical or equivalent part of the present disclosure.

Embodiment

Hereinafter the various embodiments of present inventive concept being made detailed reference, the example will illustrate in the accompanying drawings, and be described below. Although the present invention will be described in conjunction with exemplary, it should be understood that, this specification sheets and not intended to be limits the invention to those illustrative embodiments. On the contrary, the present invention is intended to not only comprise described illustrative embodiments, but also comprise also various replacement, modification, etc. jljl and other enforcement mode, it can be included in the spirit and scope of the present invention that claims limit.

The present invention relates to a kind of powder metallurgy process, it comprises the following steps: prepare liquid lubricant by the erucicamide of the ethylene bis-stearamide and 30��40wt% that mix 60��70wt% in high-temperature stirring process at 150��170 DEG C; To form solid by cooling liqs lubricant and grind this solid and prepare powdery solid lubricant; By the metal matrix powder of the powdery solid lubricant to 100 weight parts that mix 0.4��0.75 weight part prepares powder metallurgical composition; Formed body is prepared with by compression molding powder metallurgical composition. Powder metallurgic method according to certain embodiments of the present invention is progressively described below with detailed step.

The first step prepares lubricant.

In some embodiments of the present invention, the acid amides base lubricant containing ethylene bis-stearamide and erucicamide is used as lubricant, and through high-temperature stirring process with evenly dispersed lubricant composition.

That is, in certain embodiments of the invention, in the acid amides base lubricant used in field of powder metallurgy, select ethylene bis-stearamide and erucicamide, and propose the ratio of the optimum content between two kinds of components. Therefore, addition minimumization of lubricant can be made, and compression molding energy and the demoulding energy of low formed body can be maintained simultaneously. Some according to the present invention implements mode, lubricant can have the ethylene bis-stearamide of 60��70wt% and the ratio of components of the erucicamide of 30��40wt%,, in certain embodiments, further there is the ethylene bis-stearamide of 70wt% and the ratio of components of the erucicamide of 30wt%.

And then, in certain embodiments of the invention, evenly the liquid lubricant of dispersion prepares by high temperature stirring the lubricant with specific composition ratio, liquid lubricant cooling to be transformed into block solid phase and is pulverized, then by the powdery solid mix lubricant that obtains in metal matrix powder for subsequent use.

As the traditional method for the preparation of lubricant, usually, ' mechanically mixing ' method at room temperature carries out, and therefore, is evenly dispersed with a definite limitation to causing between lubricant composition. But, in embodiments of the present invention, the even dispersion between the composition of lubricant is caused by ' high-temperature stirring ' method, wherein hybrid lubricant composition, keep the temperature in mixing machine at 150��170 DEG C simultaneously, thus finally reduce the demoulding energy of formed body. Therefore, by only adding a small amount of lubricant, under not having formed body to wear and tear, the safety ground demoulding is likely. According in some lubricant preparation process implementing mode of the present invention, if the temperature of high-temperature stirring is lower than 150 DEG C, to reduction demoulding finite energy system, because there is no the ethylene bis-stearamide of evenly dispersion and erucicamide, and the formed body with high surfaceness (Ra) may being prepared. On the other hand, if the temperature of high-temperature stirring is higher than 170 DEG C, the erucicamide with low melting point can oxidized, variable color and viscosity increase, thus is unfavorable for pulverizing.

And then, in some embodiments, in order to the liquid lubricant prepared by high-temperature stirring process is transformed into solid phase, undertaken cooling and pulverizing by ordinary method. In some embodiments, liquid lubricant is cooled to convert bulk to. Now, in some embodiments, the temperature being cooled near room temperature can be carried out, and in some embodiments, carry out being cooled to 10��30 DEG C. Bulk lubricant is pulverized with metal matrix powder Homogeneous phase mixing, and in some embodiments, the average particle size particle size of the solid lubricant of pulverizing can remain on 10��40 ��m.

Next step prepares powder metallurgical composition.

In some embodiments of the present invention, powder metallurgical composition is by preparing the mix lubricant of 0.4��0.75 weight part in the metal matrix powder of 100 weight parts. In some embodiments, in the step of the powder metallurgical composition of preparation the present invention, the addition of lubricant can reduce to minimum.

Next step prepares highdensity formed body by compression molding.

In some embodiments of the present invention, compression molding is undertaken by conventional metallurgical technology. In some embodiments, it is possible to powder metallurgical composition is filled in mould, and 500��600Mpa pressure contract to prepare formed body. In some embodiments, the formed body of preparation can be separated from mould by adding the knockout press of 900��1400Kgf.

In some embodiments, the formed body prepared by aforesaid method can maintain 7.1��7.3g/cm³High-density. And then, according to the powder metallurgy process in some enforcement mode of the present invention, compared with the lubricant adding 0.75 weight part based on the metal matrix powder of 100 weight parts, when adding the lubricant of 0.4 weight part, unusual effect below can be obtained. Knockout press can reduce and reaches 200Kgf, and mould density can increase and reaches 0.18g/cm³��

The powder metallurgy process of another embodiment of the present invention can comprise the following steps:

I) prepare liquid lubricant by high-temperature stirring process, at 150��170 DEG C, wherein mix the ethylene bis-stearamide of 60��70wt% and the erucicamide of 30��40wt%;

) by cooling liqs lubricant to form solid and milled solid prepares powdery solid lubricant;

Iii) by the powdery solid mix lubricant of 0.4��0.5 weight part is prepared powder metallurgical composition in the metal matrix powder of 100 weight parts;With

) by compression molding powder metallurgical composition under the pressure of 500��600MPa, the knockout press preparation then applying 900��1100Kgf wherein has 7.2��7.3g/cm³The formed body of density.

Embodiment

The following example describes some enforcement mode of the present invention, it is not intended that restriction the present invention.

Embodiment 1: according to the ratio of components qualification knockout press change of ethylene bis-stearamide and erucicamide

It is that 50:50,55:45,60:40,70:30wt% prepare each lubricant by changing as the ethylene bis-stearamide of lubricant composition and the ratio of components of erucicamide. That is, liquid lubricant is obtained by lubricant composition being stirred 60min under the high temperature of 160 DEG C. Further, when at room temperature storing, cooling liqs lubricant is to obtain block lubricant, then pulverizes to obtain the solid lubricant of 10��40 ��m.

As iron-based powder, it may also be useful to HSPP (HyundaiSteel, pure iron powder). By in the iron-based powder of mix lubricant to 100 weight part of 0.75 weight part of above-mentioned preparation, to prepare powder metallurgical composition. Powder metallurgical composition is put into mould, then it is applied the forming pressure of 500MPa, thus obtain and there is 7.12g/cm³The formed body of density.

In order to the ratio of components qualification knockout press according to the ethylene bis-stearamide and erucicamide that form lubricant, measure knockout press according to MPIF standard 45, and its result is as shown in Figure 1.

According to Fig. 1, it is possible to find, when the ratio of components of ethylene bis-stearamide and erucicamide turns into 50; During 50,55:45,60:40,70:30wt%, knockout press reduces. That is, along with the content comprising erucicamide in the lubricant reduces, knockout press is reduced to 1100kgf from 1400kgf, and when the ratio of components of ethylene bis-stearamide and erucicamide is 70:30wt%, knockout press is minimum, is 1100kgf.

Embodiment 2: according to the change of the addition of lubricant qualification formed body density

Metallurgical method according to embodiment 1, formed body prepared by the solid lubricant being 70:30wt% with the use of the ratio of components of ethylene bis-stearamide and erucicamide, and based on the iron-based powder of 100 weight parts, along with the addition of solid lubricant turns into 0.75 weight part or 0.40 weight part respectively, measure the variable density of formed body.

In fig. 2, based on the iron-based powder of 100 weight parts, add the lubricant of 0.75 weight part, and measure the knockout press of three independent times (being labeled as first, second, and third). Showing more in the drawings of result. According to Fig. 2, knockout press is low to moderate 1100kgf, and has 7.11g/cm by applying the forming pressure preparation of 500MPa³The formed body of density.

In figure 3, compared with Fig. 2, adding the lubricant of 0.40 weight part based on the iron-based powder of 100 weight parts, the add-on of lubricant and forming pressure change, and measure the knockout press of three independent times (being labeled as first, second, and third). Showing more in the drawings of result. According to Fig. 3, knockout press is low to moderate 900kgf, and has 7.30g/cm by applying the forming pressure preparation of 500MPa³The formed body of density.

According to Fig. 2 and Fig. 3, it is possible to find, when using the lubricant that the ratio of components of ethylene bis-stearamide and erucicamide is 70:30wt%, along with the addition of lubricant is reduced to 0.40 weight part from 0.75 weight part, it is likely that knockout press reduces 200kgf. Improve the density nearly 0.19g/cm of formed body³Also it is possible.

Comparative example 1 and comparative example 2: the comparison of the knockout press in conventional metallurgical method

Prepare powder metallurgical composition by the method for embodiment 1 mixing iron-based powder and lubricant, but for preparing lubricant, implement the room temperature mechanical hybrid system (comparative example 1) as ordinary method or heated polymerizable method (comparative example 2).

In figures 4 and 5, show the ratio of components along with the ethylene bis-stearamide and erucicamide that form lubricant respectively and turn into 50; During 50,55:45,60:40,70:30wt%, measure the result of knockout press.

The comparative result of embodiment 1 and comparative example 1 and 2 is summarized in following table 1.

Table 1

Compare as above, some metallurgical method implementing mode according to the present invention, by forming the ethylene bis-stearamide of lubricant by high temperature mixing and the restriction of its ratio of components is prepared powder metallurgical composition by erucicamide within the specific limits simultaneously, along with the addition of the weight lubricant based on metal matrix powder reduces, high-density formed body can be prepared, and have up to 7.3g/cm by reducing demoulding energy³Density. And then, according to the result of above-mentioned table 1, it is also possible to keep low surfaceness.

Embodiments of the present invention are by only using the preparation process of a small amount of lubricant by lubricant, there is the density keeping low shaping energy and demoulding energy simultaneously to improve formed body, and improve the effect of surfaceness, in the preparation process of described lubricant, introduce use and the high-temperature stirring process of the lubricant with certain composition.

Therefore, according to some powder metallurgy process implementing mode of the present invention, it is possible to by the amount of lubricant being reduced to 0.4 weight part preparation based on the metal matrix powder of 100 weight parts, there is 7.3g/cm³High-density formed body.

With reference to its preferred implementation, the present invention is described in detail. But, those skilled in the art should understand that, these enforcement modes can be changed without departing from the principles and spirit of the present invention, its protection domain claims and etc. jljl limits.

Claims

1. a powder metallurgy process, it comprises the following steps:

Liquid lubricant is prepared by the erucicamide of the ethylene bis-stearamide and 30��40wt% that mix 60��70wt% in high-temperature stirring process at 150��170 DEG C;

To form solid by cooling described liquid lubricant and grind described solid and prepare powdery solid lubricant;

By the described powdery solid mix lubricant of 0.4��0.75 weight part is prepared powder metallurgical composition in the metal matrix powder of 100 weight parts; And

Formed body is prepared by powder metallurgical composition described in compression molding.

2. powder metallurgy process according to claim 1, wherein said metal matrix powder is iron-based powder.

3. powder metallurgy process according to claim 1, the step of wherein said compression molding carries out under the pressure of 500��600MPa.

4. powder metallurgy process according to claim 1, also comprises the following steps:

From mould, described formed body is deviate from by adding the knockout press of 900��1400Kgf.

5. powder metallurgy process according to claim 1,

The wherein said step preparing formed body also comprises the knockout press adding 900��1100Kgf,

The step of described compression molding carries out under the pressure of 500��600MPa,

Described formed body has 7.2��7.3g/cm³Density.