JP2023081502A - LEAD-FREE Fe-BASED POWER COLLECTION PANTOGRAPH CONTACT STRIP MATERIAL - Google Patents

Abstract

To provide a lead-free Fe-based power collection pantograph contact strip material.SOLUTION: A lead-free power collection pantograph contact strip material comprises plural kinds of powders for producing a lead-free Fe-based power collection pantograph contact strip material, in which the plural kinds of powders substitute for the conventional lead powders by silver powders, specifically, the plural kinds of powders comprise silver powders but do not comprise lead powders. The lead-free Fe-based power collection pantograph contact strip material comprises a receivable inexpensive lead-free power collection pantograph contact strip without impairing the performance of a contact strip.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a lead-free Fe-based current collecting pantograph contact strip material, and more particularly to a lead-free Fe-based current collecting pantograph contact strip material in which lead is replaced by silver.

As is well known, lead is a toxic substance and a heavy metal at the same time. Once it enters the human body, it is difficult to eliminate it from the body. has been scientifically documented, and cases of lead poisoning are constantly heard. However, the long and short pantograph sliders themselves, which are among the consumables used in large quantities for high-speed railways, also contain toxic lead.

The main function of the pantograph slider for current collection (hereinafter abbreviated as the slider) is to effectively collect the large current (500 to 1000 A) of the high voltage trolley wire of 25 to 32 kV, and the high speed rail can reach 300 km / h. It is possible to operate safely even if it reaches Pantograph sliders for current collection are mainly made of Fe-based sintered alloy containing elements such as molybdenum, titanium, and tungsten, and high-hardness particles with wear resistance added with compounds necessary for lubricity. It conforms to the following characteristics when running.

(1) good electrical conductivity; It effectively collects large currents (500-1000A) to supply the system with the necessary power.

(2) good wear resistance; Pantograph sliders for current collection are worn in direct contact with high voltage cables, and this characteristic directly affects service life and safety.

(3) high lubricating ability; The current collecting pantograph slider itself not only needs to be wear resistant, but it also rubs against the high voltage cable, so it needs to be lubricated to extend the service life of the copper cable. In addition, when the lubricity increases, the noise generated by the friction between the current collecting pantograph slider and the cable during high-speed running is also reduced.

(4) sufficient mechanical strength; The pantograph slider for current collection is used in an environment where it is an important external member for high-speed travel at 300 km/h, so it has a certain level of mechanical strength and satisfies safety requirements against accidental collisions.

In addition, since the current collecting pantograph contact strip is in contact with the trolley wire, it receives a high voltage of 25~32kV and a large current of 500~1000A at any time. I had to.

In order to satisfy the above functional requirements, conventional Fe-based current collecting pantograph contact strip materials are mainly composed of the following different powders. The multiple types of powders include high-melting-point metal powders, high-hardness wear-resistant particles, high-performance lubricating powders, and Fe-based metal powders.

The high-melting-point metal powder is selected from one or more of W, Mo, Cr, V, and Ti. High-hardness wear-resistant particles include one or more of Cr, CrV, Fe--Cr, Fe--Mo, Fe--V, Fe--W and Fe--Ti alloys (JPH05-105995A), or TaB ₂ , NbB ₂ , ZrB ₂ , TiB ₂ , ZrN, CrN, TaC, or one or more of WC (JPH08-109453A), or Fe-Mo-Si-Cr, Fe-Mo-Si any one or more of intermetallic compounds such as (JPH05-230603A).

In addition to Fe, the Fe-based metal powder may partially replace the original Fe with Cu (JPH06-158219A). 0.4 wt% nitrogen, or 2-5 wt% Sn and 0.01-0.5 wt% phosphorus may be added (JPH08-246110A and JP2013-241629A). Ni or Mn may be added to improve the toughness of the base.

The high-performance lubricating powder mainly adopts lead, metal sulfide, BN or metal silicide such as _TiSi2 , _WSi2 and _MoSi2 described in JPH08-109453A, with high hardness and wear-resistant particles at the same time. Among them, lead has the highest lubrication performance. Lead enhances the lubricity between the contact strip and the copper cable, effectively lowers the coefficient of friction, greatly reduces the amount of wear between them, and forms a very high protection. For this reason, even though lead is known to be toxic, the use of lead in Fe-based collector pantograph contact strip materials is unavoidable. In conventional patent documents, for example, the description of "Fe-based sintered current collector sliding material" in Patent Document 1 below contains 2 to 20 wt % of lead.

The lead in the Fe-based current collecting pantograph contact strip material is the same as the lead in the high-performance lubricating powder, and is evenly mixed with other high-melting-point metal powders, high-hardness wear-resistant particles, and Fe-based metal powder. Since the sintered contact strip material generally contains 5-15% porosity, except for direct sintering by compression molding, molten liquid lead is applied to lead-free contact strips for post-lead impregnation. (Lead infiltration) treatment is applied. For example, Patent Literature 2 below describes "pantograph contact strip material for current collection made of lead-impregnated Fe-based sintered alloy with excellent abrasion resistance".

Since Japan's Tokaido Shinkansen officially commenced operations in 1964, and business opportunities have arisen, high-speed railways have been rapidly constructed in many countries due to their high transport capacity, high speed and convenient advantages. was taken. Since the Taiwan High Speed Rail started its trial operation in January 2007, it has gradually improved access roads and means of transfer. It continues to set new record highs. In addition, it will provide convenient and comfortable inter-city transportation, gradually replace the traditional intra-island air market, change the work and leisure life of many people, meet the diverse needs of passengers, and create a "western corridor daily life" It has fulfilled the wish of "area".

Japanese Patent Application Publication No. 2743105B2 Japanese Patent Application Publication No. 2853563B2

However, apart from being comfortable and convenient, the pantograph long and short contact strips, which are consumables used in large quantities on high-speed trains, themselves contain toxic lead. Since pantograph sliders for current collection are worn by direct contact with high-voltage cables, powder containing worn lead is scattered along the high-speed railroad when it runs at high speed.

As is well known, lead is both a toxic substance and a heavy metal, so once it enters the human body, it is difficult to excrete from the body. is medically proven, and cases of lead poisoning continue. Although the high-speed railway is not densely populated, it is a major source of food production. When lead is absorbed into the land's crops, the food is eaten by the whole nation and enters the body, ignoring people's health. inflict irreparable harm. In densely populated urban areas, railways are underground. However, pantograph sliders for current collection of high-speed railways rub against copper cables and generate lead-containing dust during operation, so they are sealed. In the underground space, passengers waiting for trains at stations and employees of the platform can easily breathe into the human lungs.

Since the pantograph slider for current collection was developed, the composition of the slider has been continuously improved.

Summarizing the above, it can be said that the Fe-based current collecting pantograph contact strip material has a defect in the manufacturing process. As a profession, the inventor has conducted testing and research to present a lead-free Fe-based current collecting pantograph slider material that has an acceptable cost lead-free current collecting pantograph slider without compromising the performance of the slider. bottom.

Therefore, the inventor of the present invention thought that the above-mentioned drawbacks could be improved, and as a result of earnest studies, the present inventors came up with the proposal of the present invention that effectively solves the above-mentioned problems with a rational design.

The present invention has been accomplished through intensive research by the inventors in view of the above problems. To provide a pantograph contact strip for lead-free current collection.

In order to solve the above problems, one aspect of the present invention is a lead-free Fe-based current collecting pantograph contact strip material, which contains a plurality of types of powders for producing the lead-free Fe-based current collecting pantograph contact strip material, The plurality of powders replaces conventional lead powder with silver powder, ie, the plurality of powders includes silver powder but does not include lead powder.

Preferably, the plurality of powders includes a refractory metal powder, a high hardness wear-resistant particle, a high performance lubricating powder, and an Fe-based metal powder.

Preferably, the high performance lubricating powder contains 2-10 wt% of said silver powder.

It is another object of the present invention to provide a low lead compound current collecting pantograph contact strip that minimizes the lead content of the prior art without compromising the performance of the contact strip while at the same time being acceptable in price.

In order to achieve the above object, a low-lead Fe-based current collecting pantograph contact strip material according to the present invention includes a plurality of types of powder for producing the lead-free Fe-based current collecting pantograph contact strip material, powder replaces conventional lead powder with silver powder, that is, the plurality of powders includes silver powder and lead powder with a content of 0 wt% to more than 1 wt%.

INDUSTRIAL APPLICABILITY The present invention can provide a lead-free Fe-based current collecting pantograph contact strip material.

1 is a flow chart of manufacturing a conventional lead-containing current collecting pantograph contact strip material.

[Embodiment 1]
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It goes without saying that the present invention is not limited to the following examples, and can be arbitrarily modified without departing from the gist of the present invention.

First, compared to the elements used in other contact strips, lead has a relatively low melting point and good electrical conductivity. is filled in a hole of several nanometers, which lowers the electrical resistivity of the contact strip and reduces electrolytic corrosion during running of the train.

In addition, the hardness of lead is very low compared to metal materials, and the material is flexible. Therefore, as a solid lubricant for contact strips, it lowers the coefficient of friction and enhances the tribological effect. Therefore, an element that replaces lead must also have the above three characteristics.

Through screening on the periodic table, we discovered that the hardness and melting point of elements such as gold, silver, copper, aluminum, zinc, and tin are less than Fe, and have great potential to replace lead. However, since gold is expensive, it is excluded first. Also, it was found in previous experiments that the hardness of zinc is high, and particularly in the abrasion test, it was found to damage the rubbing member (copper cable), so it is excluded. Aluminum does not have high hardness, but aluminum and Fe have extremely high affinity, so they form intermetallic compounds with high hardness during high-temperature sintering, and easily damage the friction member (copper cable), so this is also excluded. do. As for the remaining three (silver, copper, and tin), in the development of pantograph sliders for lead-free current collection, the above three are added in different doses, the best composition distribution is found by the Taguchi method, and finally the wear It was verified by conducting an experiment.

FIG. 1 is a flow chart for manufacturing a conventional lead-containing current collecting pantograph contact strip material. Conventional lead-containing current collecting pantograph contact strip materials are mainly manufactured by two different methods. One is produced by directly mixing lead powder and other powder raw materials together, followed by compaction to form a green compact and primary sintering (see FIG. 1). Another approach is to first sinter the lead-free formulation and then subject the lead-free contact strip to a lead impregnation (lead infiltration) process.

Specifically, referring to FIG. 1, a flow chart of manufacturing a conventional lead-containing current collecting pantograph contact strip material comprises, for example, an Fe-based metal powder 1, a high-melting-point metal powder 2, and high-hardness wear-resistant particles 3. and a lead-containing high performance lubricating powder 4 are mixed together (eg step S1). Next, step S2 is performed, and after cold pressing molding is performed at a pressure of 6.3 to 8.0 t/cm ² , mold release is performed in step S3. The green compact taken out is sintered at a high temperature of 1150° C. or higher in a hydrogen or reducing atmosphere in step S4, cooled, and post-processed in step S5 to form a standard contact strip. Finally, step S6 is executed to analyze the performance of each item.

Based on the above-described principle, contact strips in which lead is replaced by copper and tin are used as comparative examples, using completely the same formulation and manufacturing method as the conventional lead-containing contact strips. Cu-380 and Cu-400 have a composition of weight percent other than Fe: Cr: 14.0%, Cu: 3.5%, Mo: 2.1%, W: 0.2%, S: 1.3%, C: 0.12%, and less than 0.1% Si, N, P, Mn, and the rest are inevitable impurities. The molding pressure for Cu-380 is 7.6t/cm ² and the molding pressure for Cu-400 is 8.0t/cm ² . In addition, Sn-380 and Sn-400 are Cr: 15.6%, Sn: 3.0%, Mo: 2.1%, V: 0.2%, S: 1.3%, C: 0.12%, and 0.1 % Si, N, P, Mn, and the rest are unavoidable impurities. The molding pressure for Sn-380 is 7.6 t/cm ² and the molding pressure for Sn-400 is 8.0 t/cm ² . After each test, the following results were obtained. Brinell hardness test was adopted for hardness, and the test equipment was FB-3000LC.

The experimental results in Table 1 show that the average hardness of each contact strip does not exceed 120 HBS and satisfies the range of hardness values between 80 and 120 HBS required by the standard. However, the four comparative examples have individual data evenly exceeding 120 HBS, and the average value is clearly higher than the 100 HBS of the conventional lead-containing contact strip, so there is a concern that the material is too hard and may damage the copper cable. . The electrical property test method is measured based on the JIS R 7222 voltage drop method, and the impact test is performed with reference to the JIS Z2242-05 standard, using a Tinius Olsen 64 Impacter, pendulum type impact velocity = 5.12 m / s, Pendulum impact energy = 264 ft-lbf (358 Joule), specimen run without V-notch.

The electrical properties and impact test results are shown in Table 2, respectively.

The performance test results in Table 2 show that the electrical properties of the four comparative examples all meet the JRIS E 6301 standard requirement of less than 0.8 μΩ·m. As for the impact energy, except for Sn-380, which is lower than the standard, the others meet the standard requirement of over 9.8 Joule. The tensile test equipment was a Zwick/Roell Z100 UTM, the test method was performed according to the ASTM E8/E8M-16a standard, and the tensile test results of the four comparative examples are shown in Table 3 respectively.

Although the tensile test results meet the standard requirement that the tensile resistance strength of the four comparative examples exceeds 170 Mpa, considering the performance of overall yield strength and elongation, after replacing lead with copper or tin, the contact strip It shows that the material became very brittle, ruptured without yielding, and the elongation was as low as 1.3% or less. Combining the hardness, electrical properties, tensile and impact test results, after directly replacing lead with copper or tin in the contact strip, each performance is obviously inferior to the lead-containing contact strip.

In another set of comparative examples, within the composition range of conventional lead-containing contact strips, the formulation conditions of the partial composition were changed, which reduced metal sulfides and replaced lead with copper under the same parameter conditions. Including manufacturing lead-free contact strips. The weight percent composition of Cu-80 and Cu-90 other than Fe is Cr: 18.0%, Cu: 2.6%, Mo: 2.0%, Ni: 0.2%, S: 1.2%, C: 0.05%, and less than 0.1% Si, N, P, Mn, and the rest are inevitable impurities. The molding pressure for Cu-80 is 7.6 t/cm ² and the molding pressure for Cu-90 is 8.0 t/cm ² . In addition, the weight percent composition of Cu-8W and Cu-9W other than Fe is Cr: 19.2%, Cu: 2.6%, Mo: 2.0%, V: 0.2%, S: 1.2%, C: 0.05%, and 0.1 % less than Si, N, P, Mn and the rest are unavoidable impurities, the molding pressure for Cu-8W is 7.6t/cm ² and the molding pressure for Cu-9W is 8.0t/cm ² . The test results of hardness, tensile strength, electrical properties, impact, etc. of the four comparative examples described above are shown in Table 4, and the hardness is as follows.

The experimental results in Table 4 show that the average hardness of the four pairs of contact strips does not exceed 120 HBS, satisfying the requirements of the standard, and the individual hardness data of Cu-8W and Sn-9W are both less than 120 HBS. indicates that Test results are shown in Table 5 for impact and electrical properties.

The electrical property results in Table 5 all meet the standard requirement of less than 0.8 μΩ·m, and the impact values all meet the standard requirement of greater than 9.8 Joule. The results of the tensile test are shown in Table 6.

The tensile test results show that the tensile resistance strength of the four comparative examples all meet the standard requirement of over 170 Mpa. Yield strength and elongation are superior to the first set of comparative examples (Cu-380, Cu-400, Sn-380, Sn-400).

Similarly, within the composition range of conventional lead-containing contact strips, the formulation conditions of the partial composition are changed, which reduces metal sulfides and produces lead-free contact strips in which lead is replaced by tin under the same parameter conditions. Including. The weight percentage composition of Sn-10 and Sn-20 other than the Fe group is Cr: 18.0%, Sn: 1.92%, Mo: 2.0%, S: 1.0%, C: 0.05%, and less than 0.1% Si and N , P, Mn, and the rest are unavoidable impurities. The molding pressure for Sn-10 is 7.6 t/cm ² and the molding pressure for Sn-20 is 8.0 t/cm ² . In addition, the weight percent composition of Sn-1W and Sn-2W other than Fe is Cr: 19.2%, Sn: 1.92%, Mo: 2.0%, V: 0.2%, S: 1.0%, C: 0.05%, and 0.1 % Si, N, P, Mn, and the rest are unavoidable impurities. The molding pressure for Sn-1W is 7.6 t/cm ² and the molding pressure for Sn-2W is 8.0 t/cm ² . The test results of hardness, tensile strength, electrical properties, impact, etc. of the above four comparative examples are summarized in Table 7, and the hardness is as follows.

The experimental results in Table 7 show that the average hardness of the four comparative contact strips exceeds approximately 120 HBS, with respect to impact and electrical properties, the test results are shown in Table 8.

The electrical property results in Table 8 show that one of the four comparative examples did not meet the standard requirement of less than 0.8 μΩ·m, and two comparative examples exceeded 9.8 Joule for the impact value. Indicates that the requirements of the standard are not met. The tensile test results are shown in Table 9.

The tensile test results show that all the specimens meet the standard requirement of tensile resistance strength of more than 170Mpa, but some comparative examples do not yield and break, and the elongation rate of the four comparative examples is are all too low. Therefore, when judging overall performance such as hardness, impact and electrical properties, when lead is replaced by tin, the properties are greatly inferior to those when lead is replaced by copper.

As described above, in the above-mentioned comparative examples, the contact strips in which lead is replaced by copper or tin meet the requirements of the standards for contact strips that do not partially contain lead. The cable will be damaged, and the wear resistance of the contact strip is not as good as that containing lead. Therefore, it can be said that the comparative example of the contact strip in which lead is replaced by copper or tin is not suitable.

Next, referring to FIG. 1, under the same contact strip manufacturing conditions, the present application provides a combination of multiple types of powders that replaces conventional lead or lead alloy powders with silver or silver alloy powders. The powders are Fe-based metal powder 1, high-melting-point metal powder 2, high-hardness wear-resistant particles 3, and high-performance lubricating powder 4, which are mixed together to produce a lead-free Fe-based current-collecting pantograph contact strip material. In this embodiment, the high-performance lubricating powder 4 contains 2 to 10 wt% of silver or silver alloy powder, and the conventional lead powder content of the slider is 0 wt% to more than 1 wt%, or lead-free powder. do.

Using the same method as described above, using the completely same composition and manufacturing method as the conventional lead-containing contact strip, the contact strip in which lead was replaced by silver was used as an example. 19.0%, Ag: 3.0%, Mo: 1.9%, S: 1.0%, C: 0.05%, and less than 0.1% of Si, N, P, Mn, and the rest are unavoidable impurities. The weight percent composition of Pbfree-5 other than Fe is Cr: 17.0%, Ag: 5.0%, Mo: 1.9%, S: 1.0%, and less than 0.1% Si, C, N, P, Mn, and the rest, respectively. are inevitable impurities. The weight percent composition of Pbfree-8 other than Fe is Cr: 15.0%, Ag: 8.0%, Mo: 2.0%, S: 1.1%, and less than 0.1% Si, C, N, P, Mn, and the rest It is an unavoidable impurity. The molding pressure for all three examples is 7.6 t/cm ² . Experimental results in which conventional lead powder was replaced with silver powder showed that the performance such as hardness, tensile strength, impact, and electrical properties not only met the requirements of the standard, but also matched the performance of the original lead-containing contact strip. In terms of electrical properties, it is superior to lead-containing contact strips. Hardness, tensile, impact and electrical property test results for the three examples are shown in Tables 10 and 11, respectively.

As can be seen from the hardness data results in Table 10, regardless of the average data or individual data, the above three examples are all less than 120 HBS, and several individual data are less than 100 HBS. The tensile resistance strength of the above three examples also meets the r standard requirement of more than 170 Mpa, and does not yield or break, and has a high elongation. In addition, the impact energy greatly exceeds the standard requirement of more than 9.8 Joule. Therefore, in the judgment of overall performance such as hardness, impact and electrical properties, the properties when lead is replaced by silver are all superior to those when lead is replaced by copper or tin. The electrical resistivities of Pbfree-3, Pbfree-5, and Pbfree-8, which are the most important keys affecting arc erosion, are 0.410 μΩ・m, 0.403 μΩ・m, and 0.395 μΩ・m, respectively. , all of which are superior to the conventional lead-containing contact strips of 0.453 μΩ·m and 0.438 μΩ·m. μΩ·m). In summary, the present invention completely replaces lead, which is a conventional harmful element, in conventional Fe-based current collecting pantograph contact strips, and is superior to conventional lead-containing contact strips in terms of electrolytic corrosion resistance. ing.

However, if lead has to be used due to special factors, the present embodiment provides a low lead contact strip formulation with a lead content of 0 wt % to more than 1.0 wt %. This embodiment has the same inventive effects as the lead-free embodiment. The following examples are described.

Two specimens, lowPb-2 and lowPb-9, both contained 1.0 wt% lead, and lowPb-2 and lowPb-9 contained 2 wt% and 9 wt% silver, respectively. In addition, the weight percent compositions of other elements other than Fe in the two test pieces of lowPb-2 and lowPb-9 are Cr: 19.2%, Mo: 2.0%, V: 0.2%, S: 1.2%, and less than 0.1% Si, N, P, Mn, and the rest are unavoidable impurities, and the molding pressure of the two test pieces of lowPb-2 and lowPb-9 is Both are 8.0 t/cm ² . Its hardness, tensile, impact and electrical property test results are shown in Tables 12 and 13, respectively.

As can be seen from the hardness data results in Table 12, regardless of whether they are average data or individual data, the above two examples are both less than 120 HBS, and multiple individual data are less than 100 HBS. The tensile resistance strength of the above two examples also all meet the requirements of the standard of over 170Mpa, and the situation of non-yielding and breaking does not occur, and the elongation is high. In addition, all the impact energies greatly exceed the standard requirement of exceeding 9.8 Joule. Therefore, the judgment of overall performance such as hardness, impact, and electrical properties shows that the blending of low-lead (0 wt% to over 1.0 wt%) contact strips achieves the effect of lead replacement contact strips with silver. there is The electrical resistivities of lowPb-2 and lowPb-9 are 0.418 µΩ·m and 0.375 µΩ·m, respectively, which are also superior to conventional contact strips containing 3 wt% lead, and even copper or tin. It is superior to about 0.6 to 0.8 μΩ·m of each comparative example in which lead is replaced by . As described above, due to special factors, the present invention is superior in electrolytic corrosion performance to conventional lead-containing contact strips even with low lead content of 0 wt % to more than 1.0 wt %.

In addition, the wear test was carried out using a pin-on-disk type Bruker UMT TriboLab wear tester, where the pin is a copper cable and the disk is a contact strip developed by the present application. The Pin diameter is 3 mm, the disk diameter is 38 mm, and the thickness is 10 mm. The wear speed is 1500 rpm and 3000 rpm, and the load is 7-10N. All specimens (including pin and disk) are polished with 1000 grit sandpaper prior to experimentation to eliminate experimental errors caused by different surface roughnesses. The entire wear experimental process of the five lead-free/low-lead blend contact strip specimens, such as Pbfree-3, Pbfree-5, Pbfree-8, lowPb-2, and lowPb-9, was performed very smoothly, and the friction coefficient was The measurement is stable, and the equipment does not vibrate constantly or make sharp noises like the lead-free contact strips of the comparative examples. Indicates that it is the same as the lead-containing contact strip.

Upon further analysis, the contact strip specimens of the five examples had coefficients of friction ranging between 0.17 and 0.31, consistent with conventional lead-containing contact strips and having good tribological properties. It proves that Visual inspection of the contact strip (disk) and the copper cable (pin) after the wear experiment showed that both had no significant wear, no rough, uneven scratches, and the surfaces where they contacted each other were very smooth. It can be seen that the

To summarize the above, the lead-free Fe-based current collecting pantograph slider material of the present invention replaces conventional lead powder with silver powder, does not use lead completely, and does not impair the performance of the slider. At the same time, it manufactures lead-free current collector pantograph sliders at acceptable prices.

Similarly, those skilled in the art will sinter first with a silver-free formulation and then silver-free contact strip silver impregnation (lead infiltration) by conventional lead impregnation (lead infiltration) treatment methods. silver infiltration) treatment can be performed to obtain lead-free contact strips.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

REFERENCE SIGNS LIST 1 Fe-based metal powder 2 Refractory metal powder 3 High-hardness wear-resistant particles 4 High-performance lubricating powder S1 step S2 step S3 step S4 step S5 step S6 step

The lead in the Fe-based current collecting pantograph contact strip material is the same as the lead in the high-performance lubricating powder, and is evenly mixed with other high-melting-point metal powders, high-hardness wear-resistant particles, and Fe-based metal powder. Since the sintered contact strip material generally contains 5-15% porosity, except for compression molding and direct sintering, the molten liquid lead is applied to the lead-free contact strip after the lead impregnation . (Lead infiltration) treatment is applied. For example, Patent Literature 2 below describes "pantograph contact strip material for current collection made of lead -impregnated Fe-based sintered alloy with excellent abrasion resistance".

In order to achieve the above object, a low-lead Fe-based current collecting pantograph contact strip material according to the present invention includes a plurality of types of powder for producing the lead-free Fe-based current collecting pantograph contact strip material, powder replaces conventional lead powder with silver powder, that is, the plurality of powders includes silver powder and lead powder with a content of more than 0 wt % to 1 wt % .

FIG. 1 is a flow chart for manufacturing a conventional lead-containing current collecting pantograph contact strip material. Conventional lead-containing current collecting pantograph contact strip materials are mainly manufactured by two different methods. One is produced by directly mixing lead powder and other powder raw materials together, followed by compaction to form a green compact and primary sintering (see FIG. 1). Another approach is to first sinter the lead-free formulation and then subject the lead-free contact strip to a lead impregnation (lead infiltration) treatment.

Next, referring to FIG. 1, under the same contact strip manufacturing conditions, the present application provides a combination of multiple types of powders that replaces conventional lead or lead alloy powders with silver or silver alloy powders. The powders are Fe-based metal powder 1, high-melting-point metal powder 2, high-hardness wear-resistant particles 3, and high-performance lubricating powder 4, which are mixed together to produce a lead-free Fe-based current-collecting pantograph contact strip material. In this embodiment, the high-performance lubricating powder 4 contains 2 to 10 wt% silver or silver alloy powder, and the content of the conventional lead powder for the slider is more than 0 wt% to 1 wt % , or lead-free powder. do.

Similarly, those skilled in the art would sinter first with a silver-free formulation and then sinter the silver-free contact strip with silver impregnation ( silver infiltration) treatment can be performed to obtain lead-free contact strips.

Claims (10)

A pantograph contact strip material for lead-free Fe-based current collection,
including a plurality of types of powders for producing the lead-free Fe-based current collecting pantograph contact strip material,
A pantograph contact strip material for lead-free Fe-based current collection, wherein the plurality of kinds of powders contain silver powder but do not contain lead powder. The lead-free Fe-based aggregate according to claim 1, wherein said plurality of kinds of powders include high-melting metal powder, high-hardness wear-resistant particles, high-performance lubricating powder, and Fe-based metal powder. Electrical pantograph slider material. 3. The lead-free Fe-based current collecting pantograph contact strip material according to claim 2, wherein said high-performance lubricating powder contains 2 to 10 wt % of said silver powder. A pantograph contact strip material for low-lead Fe-based current collection,
including a plurality of types of powders for producing the low-lead Fe-based current collecting pantograph contact strip material,
A pantograph contact strip material for low-lead Fe-based current collection, wherein the plurality of types of powders include silver powder and lead powder with a content of 0 wt % to more than 1 wt %. 5. The low-lead Fe-based metal powder according to claim 4, wherein said plurality of powders include high-melting metal powder, high-hardness wear-resistant particles, high-performance lubricating powder, and Fe-based metal powder. Pantograph slider material for current collection. 6. The pantograph contact strip material for low-lead Fe-based current collection according to claim 5, wherein said high-performance lubricating powder contains 2 to 10 wt % of said silver powder. A pantograph contact strip material for lead-free Fe-based current collection,
a plurality of powders and silver impregnated into the pores of the material after sintering the plurality of powders in the step of silver impregnation;
A pantograph contact strip material for lead-free Fe-based current collection, wherein the plurality of kinds of powders do not contain lead powder. 8. The lead-free Fe-based current collecting pantograph contact strip material according to claim 7, wherein 2 to 10 wt % of silver is contained in the pores of the material after sintering. A plurality of types of powder for manufacturing the pantograph contact strip material for low-lead Fe-based current collection, and silver impregnated into the pores of the material after sintering the plurality of types of powder in the step of silver impregnation. , including
A pantograph contact strip material for low-lead Fe-based current collection, characterized in that the total content of lead in the plurality of types of powder is 0 wt % to more than 1 wt %. 10. The pantograph contact strip material for low-lead Fe-based current collection according to claim 9, wherein 2 to 10 wt % of silver is contained in pores of the material after sintering.

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