CN101467315A - Spark plug - Google Patents

Abstract

A spark plug having a center electrode and/or a ground electrode with an attached spark portion. The spark portion has a base material and a protective material wherein the base material is highly resistant to spark erosion and the protective material is highly resistant to corrosion.

Description

Spark plug

The cross reference of related application

[0001] the application advocates U.S. Provisional Patent Application No.60/790,215 rights and interests, and the applying date is on April 7th, 2006, the whole disclosure of its application is considered to be the part that the application discloses, and integrates with herein by reference.

Background technology

[0002] the present invention relates to have the spark plug of contre electrode and grounding electrode.The part of at least one in this contre electrode and this grounding electrode has basis material and protective materials, to prevent the corrosion of this basis material.

[0003] spark plug is known in industry, and is used for for a long time igniting in explosive motor.The basic function of spark plug is the gas that ignites in engine cylinder, and it ignites and produces power stroke (powerstroke).Because the particular attribute of explosive motor, spark plug can be exposed in a lot of extreme conditions that taken place in the engine cylinder, comprise high temperature and various corrosive combustion gases, this has shortened the life-span of spark plug traditionally.Spark erosion also can shorten the life-span of spark plug.

[0004] electron discharge is meant that the firing tip of electrode and particularly spark plug (firing tip) corrodes impaired during operation owing to the periodicity energy of the flash arc of gasifying electrode material.Traditional spark plug has by the nickel or the formed electrode of nickel alloy that are subject to the spark erosion influence.Be to improve raw material economics, in engine, use new technology to cause more energy, jumped gap between contre electrode and the grounding electrode and long potentially arc duration to force spark by spark plug.The energy of this increase has increased the spark erosion rate of the material that is subject to the spark erosion influence, therefore, more spark plug manufacturer is no longer favored conventional nickel or the nickel alloy material that uses, then seeks the material that the extremely fireproof flower corrodes, for example platinum, iridium or platinum alloy, iridium alloy.

[0005] nickel and nickel alloy are very corrosion-resistant traditionally, but much than the alternative metals or the instead of alloy of nickel or the more fire-resistant flower erosion of nickel alloy, also corrosion-vulnerable influences.The most frequently used replacement nickel or the metal of nickel alloy are platinum, iridium or their alloy.Because platinum and iridium cost an arm and a leg usually, so expect to utilize this material to be used as firing section minimumly.Therefore, the firing section that is formed by platinum or iridium or its alloy invests on nickel or the nickel alloy contre electrode usually, and minimizes dimensionally.

[0006] platinum and platinum alloy are good in the reduction spark erosion, but the influence of their corrosion-vulnerable.In addition, platinum and platinum alloy may form alloy with combustible component when being used for firing section, therefore may form nahlock or neoplasm on this firing section.These neoplasms of long-time back can influence spark gradually or change spark gap or spark profile, have reduced the performance of spark plug thus.Further, because some combustible gas is known from experience the corrosion that causes the platinum firing section, this kind corrosion can cause the spark plug gap to change, and has reduced the performance of spark plug thus.The reduction of spark plug performance can cause engine failure, the reduction of fuel economy, and inferior engine performance.

[0007] for strengthening spark plug performance and the expansion that prevents various materials on the firing section of spark plug, a lot of spark plug manufacturer are transferred with iridium as discharge or firing section recently.Because iridium has very high fusing point, so its fire-resistant to heavens flower corrodes, but than easy oxidated and other infection under the High Operating Temperature.But manufacturers of engines increases electric stress and thermal stress by engine modifications to spark plug, to improve fuel economy, has been found that iridium at high temperature has the very unsettled state of oxidation, for example the upper limit of spark plug operation scope (800-1100 ℃).Than traditional engine, these new technology engines need provide more multipotency by spark plug, forcing the gap between contre electrode and the grounding electrode of jumping of cremating, and the operating temperature of spark plug are increased.At high temperature, the iridium firing section of spark plug may suffer serious corrosion.

[0008] in a kind of special pattern, when calcium and/or phosphorus and iridium reaction cause the firing section corrosion and corrode, thinks the corrosion that iridium can take place.Along with manufacturers of engines is attempted by the increase fuel economy of reducing friction, newer development is to contain calcium and phosphorus in combustible material relatively, therefore, allows that sometimes more oil plant infiltrates in the internal combustion chamber.Calcium and phosphorus mainly are present in the engine oil plant, especially in the fuel additive.Contain during the internal combustion in the cylinder under the situation of aerobic, calcium and phosphorus can form unstable compounds with iridium reaction, and its evaporation also causes the loss of firing section iridium.More specifically, in burning and exhaust cycle process, the calcium of gaseous state can condense on the iridium firing section of spark plug, especially the side of firing section.The calcium dissolves iridium of known fusion, and iridium easy oxidation when containing phosphorus.Therefore, the compound that forms behind the calcium iridium mixture reaction of phosphorus and oxygen and dissolving is very unstable, and is subject to evaporation or vaporization, and this has caused the loss of iridium firing section.More specifically, the side of the common corroding electrode of corrosion mechanism of phosphorus and calcium, rather than towards the spark surface of comparative electrode, this is because the activity of the lip-deep spark of spark has prevented the accumulation of corrosion deposits.Demonstrate the spark plug schematic diagram of the part loss of firing section among Fig. 1.Should also be noted that, in about 800 to 1100 ℃ temperature range and do not contain under the condition of calcium and phosphorus, iridium still may suffer oxidation, and under the condition that contains calcium and phosphorus, above-mentioned corrosion process also may take place when reaching 600 ℃ low, and this temperature is in the standard operation scope of spark plug.Certainly, when engine compresses increased, the temperature working range of spark plug will increase, thereby even under the condition that does not have calcium and phosphorus, the oxidation of iridium will more and more become a difficult problem.

Summary of the invention

[0009] to sum up, the present invention relates to a kind of spark plug, wherein at least one in contre electrode and the grounding electrode comprises firing section, and this firing section has the basis material of high fire-resistant flower erosion and the protective materialss of the various corrosion mechanism that high anti-spark plug may stand.This protective materials is a plurality of metal levels that the thin layer of metal alloy is applied to basis material or forms with this basis material.This protective materials or overcoat are formed by nickel or nickel alloy, and its thickness is less than 0.09mm.And in the spark plug manufacture process, protective materials diffuses into basis material basically, at thin alloy-layer of outer surface formation of premature material.Basis material can be made up of the various elements that are widely used in spark plug, comprises platinum, palladium, rhodium, iridium, ruthenium, rhenium or its alloy.

[0010] other range of application of the present invention will from following embodiment, claim, and accompanying drawing further specify.But, having shown the preferred embodiment of the present invention though should be appreciated that these specific descriptions and specific example, they only are used for illustration purpose, and the many changes and improvements in purport of the present invention and scope are conspicuous to those skilled in the art.

Description of drawings

[0011] below in conjunction with appended claim, accompanying drawing provides preferred embodiment of the present invention, enables to understand better function, the characteristics of this reality invention.Wherein:

[0012] Fig. 1 is by the illustrative diagram of the iridium firing section of heavy corrosion;

[0013] Fig. 2 is the partial cross section figure of spark plug;

[0014] Fig. 3 is the amplification sectional view of contre electrode that comprises the firing section of spark plug;

[0015] Fig. 4 is the amplification sectional view of contre electrode that comprises the firing section of spark plug;

[0016] Fig. 5 is the amplification sectional view of contre electrode that comprises the firing section of spark plug;

[0017] Fig. 6 is the amplification sectional view of contre electrode that comprises the firing section of spark plug;

[0018] Fig. 7 is the amplification sectional view of contre electrode that comprises the firing section of spark plug;

[0019] Fig. 8 is the amplification sectional view of contre electrode that comprises the firing section of spark plug;

[0020] Fig. 9 is the amplification sectional view that comprises the grounding electrode of firing section;

[0021] Figure 10 is the amplification sectional view that demonstrates the firing section of diffusion term;

[0022] Figure 11 is the amplification sectional view of contre electrode that comprises the firing section of spark plug, and this part had the multilayer proofing material before protective materials and basis material diffusion; And

[0023] Figure 12 is the amplification sectional view that comprises the grounding electrode of firing section.

Embodiment

[0024] as shown in the figure, the relevant a kind of spark plug 10 (Fig. 2) of the present invention, it has grounding electrode 12 and contre electrode 20.Contre electrode 20 and/or grounding electrode 12 comprise firing section 30.Firing section 30 can bond, weld 38 or otherwise be engaged in contre electrode 20 (Fig. 2) and/or grounding electrode 12 (Fig. 9).

[0025] firing section 30 comprises basis material 36 and general protective materials 34 (Fig. 3-9) as skin or overcoat.As shown in figure 10, protective materials 34 can with basis material counterdiffusion mutually, thereby be formed on the firing section 30 of no evident layer between protective materials 34 and the basis material 36.More specifically, basis material 36 is mainly formed by the material that fire-resistant flower corrodes, for example iridium (Ir), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), rhenium (Re) or their alloy.The most frequently used element comprises platinum and iridium in above-mentioned group.The representative additive that is used to form above-mentioned basis material alloy comprises one or more elements of choosing from the group of being made of iridium, platinum, palladium, rhodium, ruthenium, rhenium, zirconium (Zr), nickel (Ni) and tungsten (W).The another kind of representative basis material 36 that is formed by alloy is described in greater detail in U.S. Patent application No.11/691, and in 288, the applying date is on March 26th, 2007, is called by " spark plug ".Although the present invention is thought of as basis material with iridium or platinum or iridium alloy or platinum alloy, the present invention is not limited to use iridium or platinum or iridium alloy or platinum alloy as basis material.Another exemplary iridium alloy that is suitable for use as basis material comprises the iridium of 94% to 99% weight ratio, the rhodium of 1% to 3% weight ratio, the tungsten of 0.1% to 1.5% weight ratio and the zirconium of 0.01% to 0.1% weight ratio.For big industrial spark plugs, basis material has the diameter of about 1.8mm to 4mm usually, is 0.4mm to 2.1mm for vehicle spark plugs, and is 0.25mm to 2.1mm for model with (hobby) spark plug.

[0026] protective materials 34, when combining with basis material, prevent that basis material from containing corrosion and oxidation under calcium and the phosphorus condition.Protective materials 34 is made up of anticorrosive and element oxidation.In the present invention, protective materials 34 is made up of nickel or nickel alloy.Alloy among the embodiment comprises the nickel of 85% weight ratio and the chromium of 15% weight ratio.

[0027] protective materials 34 can be by above-mentioned single alloy composition, but each element can be arranged in the independent layer on the basis material.Have been found that the pantostrat of independent each individual element that is provided with, rather than alloy, the abundant protection of expectation is provided, and has reduced material cost.For example,, can copper be used as ground floor, by follow-up electro-plating method nickel be used for skin then by electroplating if basis material is iridium or iridium alloy.Certainly, chromium can replace copper and reaches similar anticorrosion effect.Certainly, can use different order settings, as long as nickel is internal layer and directly contacts with basis material.The inventor also finds, any setting to the layer of protective material that comprises copper, nickel and chromium all is fine, but, a kind of concrete useful protective layered material forms in the following manner: the ground floor 34a of copper is electroplated onto basis material 36, join the second layer 34b of chromium to copper by electroplating operations, join the 3rd layer of 34c of nickel to chromium by electroplating operations then, shown in the sectional view that amplifies among Figure 11.But, should be noted that these single layers can spread jointly with basis material subsequently.

[0028] spark results from the edge 44 of firing section usually, because the fire-resistant flower of nickel corrodes, protective materials must be shaped to enough thin layer, with during the spark plug continuous running, the spark in jump spark gap 14 is mainly resulted from the basis material 36, rather than on the protective materials 34.In certain embodiments, easy for making, discharging surface 40 also can scribble sacrificial protective material 36, and it is corroded on discharging surface 40 in the course of the work, but is retained in the side of firing section 30, the corrosion when preventing to have calcium and phosphorus.Therefore protective materials 34 generally has the thickness less than 0.09mm.Thickness of interpolation is 0.002 to 0.018mm layer on basis material 36, makes basis material have enough corrosion resistances, also can avoid spark erosion simultaneously.Because protective materials 34 is extremely thin material layers, the variation in any gap that spark erosion causes can not influence the performance of spark plug basically.And, be subject to the zone of spark erosion, as side surface, generally also be not vulnerable to cremate and corrode, and protective materials can prevent that the side from being corroded.Because the spark activity has stoped corrosion mechanism when containing phosphorus and calcium, the edge 44 of firing section 30 and discharging surface 40 corrosion-vulnerable not usually when containing phosphorus and calcium.

[0029] in the illustrated execution mode, firing section 30 is shaped to column or polygon, and it has exterior periphery 42 and first end or discharging surface 40.The end of discharging surface 40 joins contre electrode 20 to relatively.Contre electrode 20 is formed by nickel or nickel alloy usually, but also can use other element or alloy, for example the iron-based contre electrode.As shown in the figure, protective materials 34 does not extend above first end or discharging surface 40.When discharging surface 40 continue to discharge spark by it during operation,, minimum or do not exist to the corrosion of discharging surface because pyrophoric behavio(u)r is isolated with corrosive elements basically with discharging surface.

[0030] as mentioned above, for preventing spark erosion, firing section 30 can be by the protective materials of methods such as plating, sputter, flame-spraying or plasma coated coating one deck less than 0.09mm.Therefore, accumulate or the quantity of material that deposits to the protective materials 34 of basis material 36 is minimum.Therefore, enough protective materialss deposit to the exterior periphery of basis material, minimize to form highly corrosion resistant firing section 30, to make simultaneously the quantity of material that is deposited in the excessive gap that the spark surface is used to prevent that spark erosion from producing.

[0031] by using above-mentioned thin layer, spark plug components in spark ignition process or in the manufacture process in the smelting furnace, and spark plug is in in-engine potential subsequent operation process, protective materials 34 diffuses into basis material 36, thereby protective materials and basis material are diffused into together, so that the boundary that cuts edge really between protective materials 34 and the basis material 36 is difficult to determine, as shown in figure 10.More properly, because basis material 36 spreads with protective materials 34 mutually around exterior periphery, in cross sectional view, firing section 30 is near the exterior periphery 42 mainly being that protective materials passes diffusion zone 90, along with the center of closing on basis material, the amount of protective materials reduces (Figure 10) gradually in this zone.Fig. 3-10 has shown before the diffusion protective materials 34 to the amplification form of thickness.As shown in figure 10, shown layer externally circumference place is about 100% protective materials, shown in inner boundary 91 places be reduced at least 10%, even in case do not have clear and definite border after spreading.More specifically, the diffusion zone 90 of protective materials from its material almost 100% exterior periphery 42 that forms by protective materials 34 extend towards the center 32 of firing section 30, basically account for the principal status of public economy until basis material 36, for example in its weight ratio of given area that forms inner boundary 91 greater than 90%.As shown in figure 10, can find the zone 64 of basis material and protective materials equivalent.Those skilled in the art will appreciate that for clear expression visually with respect to the opinion in description or claims in the specification, what the relative basis material of layer of protective material shown in Fig. 3-9 or diffusion zone will be thick is many.

[0032] because the spark plug of operating condition has basis material 36 that diffuses into protective materials 34 and the protective materials 34 that diffuses into basis material 36, in operating process, be difficult to protective materials 34 and basis material 36 are separated, because of producing thicker clad material.For example, have the outer field coating matrix of thickness greater than 0.12mm, more specifically, thickness is greater than 0.25mm, this coating matrix has different thermal characteristics (thermal profile) because of different materials, when spark plug between hot cold cycling during continued jitters these materials can be separated from each other in time.Therefore,, rather than have tangible single layer,, thereby increased the operation lifetime of spark plug because of the increase of its anti-spark erosion, the increase of corrosion resistance and the increase of durability because spark plug has the thin layer that diffuses into basis material.

[0033] comprises that the spark plug 10 of firing section 30 can be by any known method manufacturing.The manufacturing of spark plug is known, and is included in to add firing section 30 on contre electrode 20 and/or the grounding electrode 12.In the present invention, spark plug 30 can bonding, resistance welded, laser welding or join contre electrode 20 and/or grounding electrode 12 to by any well-known process.Spark plug 10 generally includes metal shell, insulator and is arranged at the interior contre electrode 20 of this insulator, thereby the firing section 30 on the contre electrode 20 is outstanding to grounding electrode 12, and has discharging surface 40 (Fig. 2).

[0034] this insulator is typically formed by aluminium, and has the passage that contre electrode 20 can pass through its extension.This metal shell is formed by the cylindrical metal sleeve pipe, comprises the threaded portion that screws in engine pack.This metal shell is typically formed by straight carbon steel, but also can be stainless steel or other material.

[0035] common, firing section 30 at first passes through from forming basis material 36 and moulding by platinum, palladium, rhodium, iridium, ruthenium, rhenium or its alloy.The basis material 36 of firing section 30 can form by any known method.Basis material 36 can form Metal Flake, discoid, filament shape or bar-shaped by hot forming, hot rolling or hot wire drawing.The another kind of way of moulding basis material 36 is to utilize metal dust, and with this powder melts to form basis material 36.Can carry out this melt process by electric arc melting, electron beam melting, lf, high frequency conduction fusion, plasma melting or other known method.

[0036] after basis material 36 roughly is shaped to intended shape (being generally long and narrow bar-shaped or silk thread), protective materials 34 is added to the basis material 36 that is shaped to bar-shaped or silk thread.Can be by adding protective materials 34 such as technologies such as the electrolysis on the electroless plating layer, electro-deposition, sputter, flame-spraying or co-extrusions.Importantly, when adding base layer to, the thickness of overcoat is not more than 0.09mm.Certainly, can on the basis material outer surface, provide any other means to can be used for adding protective materials 34 to basis material 36 less than the thin layer of 0.09mm.In case cremate part 30 is formed by the protective materials 34 in the outside of basis material 36, this long and narrow part is cut, punching press or be pressed into suitable length, and these single sheet materials are suitable for joining to contre electrode 20 or grounding electrode 12.

[0037] method that firing section is joined on grounding electrode 12 and/or the contre electrode 20 comprises that welding (for example electric resistance welding, Laser Welding or other means) is to central authorities or grounding electrode 12/20.Another kind method is to form impression or indenture on the outer surface of firing section 30, to produce mechanical locked mechanism (figure does not show).Contre electrode 20 is drilled out to the diameter identical with firing section 30, and with firing section 30 insert in the hole (Fig. 7).Utilize then such as LASER HEATING contre electrode 20, thereby metal and is formed in the indenture of outer surface around firing section 30 fusions of inserting.Certainly, can implement other forming operation, for example be manufactured with the rivet (headed rivet) of head, then as known in the art, firing section can be joined to contre electrode 20 firing section 30.In addition, firing section 30 can join another silk thread or disk and welding to thereon, is welded to contre electrode 20 then, to strengthen combining of contre electrode 20 and firing section 30.

[0038] contre electrode 20 that shows among Fig. 3 is welded direct to contre electrode 20, contre electrode 20 can be treated reducing the diameter of contre electrode nickel termination 21, and provide cavity 22 to be used to hold firing section 30.Firing section 30 can comprise various configurations, for example as forming integrated firing section 30 from more than one materials, applies protective materials then.More specifically, as an example, can partly form firing section by nickel part and iridium, it is assembled to (Fig. 6) on the contre electrode.Protective materials 36 can cover each several part, and applies before or after being assembled to contre electrode.Shown in Fig. 3 and 4, firing section 30 can at first be handled to utilize protective materials 34 coated substrates parts 36.After firing section 30 applied protective materials 34, it was welded to contre electrode 20.Because of being welded to contre electrode 20, firing section 30 produces molten bath (weld pools) 38.In Fig. 5,6, when basis material 36 joins contre electrode 20 after-applied firing sections 30 to.More specifically, basis material 36 joins contre electrode 20 to, and protective materials 34 is applied to contre electrode 20 and basis material 36 then.This has allowed easily used protective materials in manufacture process.In Fig. 6, the multilayer rivet forms firing section, and it makes basis material join another kind of material 33 to, typically is nickel alloy.Following document discloses a kind of embodiment of integrated firing section 30: U.S. Patent Application Serial Number No.11/602, and 028, the applying date is on November 20th, 2006, name is called " forming method that has the spark plug of multi-layer firing termination "; U.S. Patent Application Serial Number No.11/602,146, the applying date is on November 20th, 2006, name is called " spark plug that has the multi-layer firing termination "; And U. S. application sequence number No.11/602,169, the applying date is on November 20th, 2006, name is called " spark plug that has the multi-layer firing termination "; It is all quoted and incorporates the present invention into.As mentioned above, only firing section comprises layer of protective material, and perhaps contre electrode and body portion can comprise layer of protective material.Protective materials 34 is coated to this multilayer rivet to form firing section 30.This multilayer rivet firing section 30 joins contre electrode to then, as passing through welding.Multilayer riveted joint shown in Figure 6 applies protective materials then to contre electrode, still, also can at first apply protective materials and engage then.Fig. 9 has shown the firing section 30 that joins grounding electrode 12 to.

[0039] protective materials can further be strengthened by chemistry or heat treated.Heat treatment can be carried out before or after firing section 30 is engaged in contre electrode.For example, in the last ignition process of spark plug 10, can carry out the heat treatment of firing section 30, thereby being connected because of overcoat 34 diffuses into basis material 36 of basis material 36 and overcoat 34 strengthens.The generation of diffuse makes interface between two-layer produce the boundary layer of diffusion rather than clear and definite border.In addition, because two kinds of materials similar, and respectively have the part that another diffuses into, the tightr connection of molecular level has been allowed in the diffusion between two-layer, simultaneously have the anti-spark erosion of expectation at discharging surface, and the corrosion resistance of the expectation on the circumference externally.Therefore, enough protective materialss deposit to the exterior periphery of basis material, minimize to form highly corrosion resistant firing section 30, to be used in simultaneously the quantity of material that prevents near excessive spark erosion edge 44.

[0040] in manufacture process, protective materials diffuses in the basis material at least in part, and it provides the protection that prevents the reinforcement of corroding.More specifically, in the ignition process of glass capsulation, for example be higher than under 530 ℃ the temperature, protective materials begins to diffuse in the basis material.For example, when nickel protective materials 34 began to diffuse into the basis material 36 of iridium, the iridium nickel alloy provided the protection of the reinforcement that surmounts nickel or iridium self performance.Therefore, protective materials forms diffusion zone 39, as shown in figure 13.Diffusion zone 90 provides protection, even Kuo San protective materials 34 does not erode away.In addition, have been found that basis material and combining of protective materials provide the protection of strengthening.More specifically, when spark plug typically at about 750 ℃ to 1000 ℃ temperature down-firing when forming glass capsulation, protective materials begins to diffuse into basis material to form diffusion zone 39.Diffusion zone moves from the center of firing section, and it mainly is collective's material, and until arriving at regional 79 o'clock, basis material and protective materials exist with the amount that approximately equates, mainly is protective materials when moving closer to the external margin of firing section 30 then.Diffusion zone 39 also closes on the exterior section of firing section 30.According to the thickness of the protective materials that applies, diffusion zone can not be exposed in manufacture process, so outer surface only is a protective materials.Usually the thickness of diffusion zone is less than the thickness of the overcoat that is applied, and typical, its thickness is less than 0.007mm, and is preferred, less than 0.005mm.

[0041] the above discussion discloses and described exemplified embodiment of the present invention.Those skilled in the art will readily understand, by above-mentioned discussion, and by accompanying drawing and accompanying Claim, under the prerequisite that does not depart from the proper range of the present invention that limits by following claim and purport, can carry out multiple change, correction and modification it.

Claims (35)

1, a kind of spark plug, have contre electrode and grounding electrode, and at least one of wherein said contre electrode and described grounding electrode comprises firing section, and described firing section comprises basis material and the protective materials of being made up of nickel, and the thickness of this protective materials is less than 0.09mm.

2, spark plug according to claim 1, wherein said basis material comprise at least a element of choosing from the group of being made of platinum, palladium, rhodium, iridium, ruthenium, rhenium.

3, spark plug according to claim 1, wherein said basis material comprise the alloy of at least a element of choosing from the group of being made of platinum, palladium, rhodium, iridium, ruthenium, rhenium.

4, spark plug according to claim 1, wherein said protective materials comprise at least a element of choosing from the group of being made up of copper, chromium, vanadium, zirconium, tungsten, osmium, gold, iron and aluminium, the content of this element is less than 15% of described protective materials.

5, spark plug according to claim 1, wherein said protective materials comprise about 85% nickel and about 15% chromium.

6, spark plug according to claim 1, wherein said protective materials is made up of nickel basically.

7, spark plug according to claim 1, wherein said spark plug is the thin-and-long with first end and excircle, wherein said basis material and described protective materials define first end, and described protective materials defines the whole of described excircle substantially.

8, spark plug according to claim 1, wherein said protective materials is electroplated on described basis material.

9, spark plug according to claim 1, wherein said protective materials is by sputter, or electrolysis, or extrudes, or flame-spraying is applied to described basis material.

10, spark plug according to claim 1, wherein said basis material comprise outside matrix circumferential surface, and described protective materials diffuses into described basis material at least in part.

11, spark plug according to claim 1, wherein said basis material comprise outside matrix circumferential surface, and wherein when described firing section is heated to more than 530 ℃, the border between described basis material and described protective materials forms diffusion alloy.

12, spark plug according to claim 1, wherein said basis material comprises outside matrix circumferential surface, and wherein be heated to about 760 ℃ between 820 ℃ the time when described firing section, to be diffused in the border between described basis material and the described protective materials, to form the diffusion alloy of this basis material and protective materials.

13, spark plug according to claim 1 also comprises a diffusion zone, is adjacent to the outer surface of described spark plug.

14, spark plug according to claim 1 also comprises the zone that the alloy of a basis material and protective materials forms.

15, spark plug according to claim 1, the thickness of the described protective materials that is applied in is between 0.005mm to 0.09mm.

16, spark plug according to claim 15, the thickness of the described protective materials that is applied in is between 0.005mm to 0.025mm.

17, spark plug according to claim 16, wherein said protective materials is applied in as the layer that has less than 0.25mm thickness.

18, spark plug according to claim 15, wherein said firing section comprise the diffusion zone of a thickness less than the described protective materials that is applied in.

19, spark plug according to claim 15, wherein said firing section comprise the diffusion zone of a thickness between 0.005mm to 0.09mm.

20, spark plug according to claim 1, wherein said firing section comprise a diffusion zone that extends to the center from the outer circumferential surface of described firing section, and the thickness of this diffusion zone is less than 0.025mm.

21, spark plug according to claim 1, wherein said firing section comprise a diffusion zone that extends to the center from the outer circumferential surface of described firing section, and the thickness of this diffusion zone is less than 0.012mm.

22, a kind of spark plug, have contre electrode and grounding electrode, and at least one of wherein said contre electrode and described grounding electrode comprises firing section, described firing section comprises basis material and the protective materials of being made up of nickel, it is characterized in that described protective materials is as for the described basis material that diffuses into of part.

23, spark plug according to claim 22 is characterized in that described basis material comprises a kind of element of choosing from the group of being made up of platinum, palladium, rhodium, iridium, ruthenium, rhenium.

24, spark plug according to claim 22 is characterized in that described basis material is the alloy that comprises at least a element of choosing from the group of being made up of platinum, palladium, rhodium, iridium, ruthenium, rhenium.

25, spark plug according to claim 22, it is characterized in that described protective materials further comprises at least a element of choosing from the group of being made up of copper, chromium, vanadium, zirconium, tungsten, osmium, gold, iron and aluminium, the content of this element is less than 15% of described protective materials.

26 spark plugs according to claim 22, wherein said protective materials comprise about 85% nickel and about 15% chromium.

27, spark plug according to claim 22, wherein said spark plug is the thin-and-long with first end and excircle, wherein said basis material and described protective materials define first end, and described protective materials defines the whole of described excircle substantially.

28, spark plug according to claim 22, the thickness of described protective materials is less than between the 0.09mm.

29, spark plug according to claim 22, wherein said protective materials is electroplated on described basis material.

30, spark plug according to claim 22, described protective materials diffuses into described basis material at least in part.

31, spark plug according to claim 30, when described firing section was heated to more than 530 ℃, the border between described basis material and described protective materials formed diffusion alloy.

32, spark plug according to claim 19, described basis material and described protective materials match at diffusion zone.

33, spark plug according to claim 32, described diffusion zone are formed by the alloy of nickel and a kind of material of choosing from the group of being made up of platinum, palladium, rhodium, iridium, ruthenium, rhenium substantially.

34, spark plug according to claim 32, described diffusion zone comprise first side and second side that the cross section is arranged therebetween, and wherein said first side is mainly formed by basis material, and described second side is mainly formed by protective materials.

35, spark plug according to claim 34, the cross section of described diffusion zone is by the described basis material and the described protective materials of ratio form about equally.

36, spark plug according to claim 32, wherein said protective materials diffuse into after the described basis material, and a spot of basis material appears at the outer circumferential surface of firing section.

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