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添加剂复配对氧化铝陶瓷和金属副摩擦学性能的影响

添加剂复配对氧化铝陶瓷和金属副摩擦学性能的影响
添加剂复配对氧化铝陶瓷和金属副摩擦学性能的影响

Synergistic effect of diisopropyl phosphite and over ‐based calcium sulphonate additives on tribological properties of AISI 52100steel/Al 2O 3ceramics

Shuyun Jiang *,?and Hongjun Xie

School of Mechanical Engineering,Southeast University,Nanjing 211189,China

ABSTRACT

The friction ‐reducing and anti ‐wear effect of the 500SN base oil containing diisopropyl phosphite (T451)and over ‐based calcium sulphonate (KT5447)on AISI 52100steel/Al 2O 3ceramic were investigated with a ball ‐on ‐disc tribometer at a light load of 200N and a high load of 400N.The results indicate that the 500SN base oil containing T451and KT5447appears to have a synergistic effect on the pair.For the light load of 200N,the effective composition is 3wt%T451+2–3wt%KT5447.For the high load of 400N,the combination of T451and KT5447appears to have a synergistic friction ‐reducing and anti ‐wear effect.The scanning electron microscope images show that ploughed grooves,pitting,spalling and corrosion are the dominant wear modes for both 200and 400N.However,no evidence for the formation of the expected sulphur ‐containing or phosphorus ‐containing chemical compound is found according to X ‐ray photoelectron spectroscopy analysis of the worn steel ball surface at both loads.Copyright ?2011John Wiley &Sons,Ltd.

Received 26October 2010;Revised 8March 2011;Accepted 9March 2011

KEY WORDS:steel ;ceramics;additive;additive interaction;wear;mechanism

INTRODUCTION

Due to its outstanding tribological properties including low friction coef ?cient,high wear and corrosion resistance,advanced alumina ceramics have received increasing attention in engineering applications.The tribological behaviour of alumina ceramics has been systematically studied,and the operating parameters concerned include load,sliding speed,surface roughness,temperature and lubrication condition.The results show that the tribological performance of alumina ceramics can be substantially improved by using liquid media for lubrication.1–6

Alumina mating with steel has been widely used in industry due to its outstanding property of wear resistance and others.The effects of oil additives on the alumina/steel pair have attracted broad *Correspondence to:Shuyun Jiang,School of Mechanical Engineering,Southeast University,Nanjing 211189,China.?E-mail:jiangshy@https://www.wendangku.net/doc/ec3582498.html,

LUBRICATION SCIENCE Lubrication Science (2011)Published online in Wiley Online Library (https://www.wendangku.net/doc/ec3582498.html,).DOI:10.1002/ls.155

Copyright ?2011John Wiley &Sons,Ltd.

attention in recent years.7–10For example,tributyl phosphate shows good anti‐wear(AW)property at a high‐load condition in a four‐ball wear test,and trialkyl phosphite with long carbon chains was reported to reduce the friction coef?cient of the pair.

Lubricating oils,which contain various types of oil additives,are normally a multicomponent additive system;the synergistic effect of the friction‐reducing or AW performance can occur when the proper oil additives have been used.It was reported that the selected combination of friction modi?er (FM)and extreme pressure(EP)and AW additive resulted in marked enhancement in EP/AW properties and a substantial improvement in friction‐reducing behaviour.11–17However,there is still a lack of comprehensive understanding of the tribological behaviour of alumina sliding against steel;the fundamental mechanism of boundary lubrication under the combination of FM and EP/AW has not been studied thoroughly due to their complex competitive nature in forming protective layers on the interface.18

The previous work about the tribological behaviour of T8steel/Al2O3ceramics shows that diisopropyl phosphite(T451)exhibits desirable friction‐reducing effect.19–22Recently,the investigation by the author revealed that over‐based calcium sulphonate(KT5447)presents remarkable AW property.In view of this,the main aim of this study is to(i)investigate the friction‐reducing and AW effect of the combination of T451and KT5447on the AISI52100steel/ Al2O3ceramics and(ii)attempt to reveal the cause of these effects by surface analysis.

EXPERIMENTAL PROCEDURE

Specimens and lubricants

A ball‐on‐disc tribometer(Figure1)was used to investigate the tribological behaviour of52100/Al2O3 under base oil containing T451and https://www.wendangku.net/doc/ec3582498.html,mercial bearing ball of52100steel of6mm in diameter is mated to alumina disc.The steel ball rotates at a set speed,sliding on the?xed Al2O3disc

specimen.The hardness of52100steel ball is61–65HRC,and the initial surface roughness of both the ceramic disc and the steel ball can reach Ra0.0125μm by polishing and grinding systematically. The paraf?n neutral oil500SN is used as the base oil,which possesses a kinematics viscosity of 61.2–74.8mm2s?1at40°C.Lubricant samples are made from the base oil blended with FM T451and EP/AW KT5447in various percentages,and the total base number of KT5447is about 400mgKOH g?1.The structural formulae of two additives are presented in Figure2.The base oil and the additives T451,KT5447are acquired from three chemical companies;their names are withheld for reason of con?dentiality.

Experimental procedure

Tribological experiments were conducted in air at room temperature(23°C)and relative humidity of 30–35%.Prior to the formal test study,series of trial tests had been conducted to acquire the Stribeck curve of the tribopair;according to this curve,a relative sliding velocity of0.125m s?1was used to ensure that the pair is at the boundary lubrication condition,which is needed to study the tribological behaviour of the pair under the oil additives.As stated above,T451is an FM,which is effective for the light load condition,and KT139is an AW additive,which is for the heavy load condition.A trial tribotest under single T451or single KT139had been conducted,according to the relationship between the friction coef?cients with the normal loads;the load of200N(resulting in a maximum Hertzian pressure of2.28GPa)was adopted to assess the friction‐reducing performance of T451,and the load of400N(maximum Hertzian pressure of2.78GPa)was used to assess the AW behaviour of KT139.The wear scar diameter(WSD)of52100steel ball was measured by an optical microscope with an accuracy of0.01mm in both X and Y directions.Before or after each test,the specimens were cleaned with acetone in an ultrasonic cleaner.All reported results are the average values of at least three test runs.The worn surface morphologies were examined by the FEI Quanta200scanning electron microscope(SEM;FEI Company,Hillsboro,OR,USA).In addition,the chemical analysis of tribo?lms was also performed by X‐ray photoelectron spectroscopy(XPS)(PHI‐5702;Physical Electronics Inc.,Chanhassen,MN,USA)probing a depth to a few nanometers(5nm)in the tribo?lm focusing in the wear scar of the area of500×500μm2.

EXPERIMENTAL RESULT AND DISCUSSION

At200N

Friction coef?cient.The effect of the combination of T451and KT5447on the friction coef?cient of

52100/Al2O3at200N is shown in Figure3.The pair shows quite large friction coef?cient with the

additive ‐free mineral base oil alone,and the values keep increasing within the entire test duration.It should be pointed out that the physical adsorption oil ?lm will form on the steel ball surface under the non ‐polar 500SN oil.A possible explanation to the rapid increase in friction coef ?cient with the test duration may be due to the fact that the rupture of the oil ?lm will intensify gradually with the increase in the interfacial temperature.Figure 3also shows that T451reduces the friction for the pairs markedly compared with the base oil alone,and the friction coef ?cients decrease monotonously with the increase of mass concentration.

Prior to the experiment in the combination of KT5447to T451,the effect of the single additive on the tribological behaviour of the pair was studied;the results show that the appropriate adding amount is from 1to 3wt%for each of the additive.Thus,within the recommended adding amount,a group of blending ratio of KT5447to T451with an increment of 1wt%is tested to obtain the appropriate combination of the oil additives and the variation of the friction ‐reducing and AW behaviour with their adding amount.By the way,this is an often ‐used test method for assessing the effect of two oil additives in tribotest.

As shown in Figure 3,the base oil containing T451and KT5447appears to have the synergistic friction ‐reducing effect.In detail,the friction coef ?cient is sensitive to the percentage of T451.As the percentage of T451is 1wt%,the friction coef ?cient decreases remarkably with the increase of KT5447;however,as the percentage of KT5447is beyond 2wt%,the effect of KT5447on the friction coef ?cient can be neglected;the friction coef ?cient curve under 1wt%T451+2wt%KT5447is almost coincident with that under 1wt%T451+3wt%KT5447,and the friction coef ?cients are less than 0.10after the running ‐in period.As the percentage of T451is 2and 3wt%,the friction coef ?cients vary

slightly Figure 3.The friction coef ?cient at the load of 200N under different lubrication system.

S.JIANG AND H.XIE

Copyright ?2011John Wiley &Sons,Ltd.Lubrication Science (2011)

DOI:10.1002/ls

with the increase in KT5447.Within the obtained experimental data,1wt%T451+2wt%KT5447and 1wt%T451+3wt%KT5447lead to the most ef ?cient friction reduction.

Wear.Figure 4shows the comparison of WSD of the 52100balls under lubrication systems at 200N.The WSD of the steel ball can reach 1.44mm under the base oil.The base oil containing T451alone decreases wear rates of steel balls dramatically;Similar with the variation of friction coef ?cient,the wear rate of the steel ball decreases monotonously with the increase in percentage of T451.

As shown in Figure 4,the base oil containing T451and KT5447appears to have the synergistic AW effect on the pair.In general,the wear rate of the steel ball decreases with the increase in T451under the compound system.As the percentage of T451is 1wt%,the wear rate decreases with the percentage of KT5447changed from 1to 2wt%and then increases as the percentage is beyond 2wt%.As the percentage of T451is 2wt%,the wear rate of the steel ball increases slightly with the increase in KT5447.As the percentage of T451is 3wt%,the wear rate decreases slightly with the increase in KT5447.In a word,similar with the variation of the friction coef ?cient,the effect of KT5447amount on the AW property of the lubricant can also be neglected when the percentage of T451is beyond 1wt %.Within the experimental data obtained,3wt%T451+2–3wt%KT5447appears to have the best AW effect;WSD of the steel ball can be less than 0.90mm.

In summary,the 500SN base oil containing FM T451and EP/AW KT5447appears to have the synergistic friction ‐reducing and AW effect on AISI 52100steel/Al 2O 3ceramic at the light load of 200N,and the most effective mass concentration is 3wt%T451+2–3wt%

KT5447.

Figure 4.Effect of additives on wear rate of 52100steel ball (200N).

ADDITIVES ON AISI 52100STEEL/AL 2O 3CERAMICS

Copyright ?2011John Wiley &Sons,Ltd.Lubrication Science (2011)

DOI:10.1002/ls

S.JIANG AND H.XIE

Figure5.Scanning electron microscope images of the worn surfaces of steel ball(applied load,200N; lubricant containing(a)1wt%T451,(b)2wt%T451,(c)3wt%T451,(d)1wt%T451+1wt%KT5447,(e) 1wt%T451+2wt%KT5447,(f)1wt%T451+3wt%KT5447,(g)2wt%T451+1wt%KT5447,(h)2wt% T451+3wt%KT5447,(i)3wt%T451+1wt%KT5447and(j)3wt%T451+3wt%KT5447).

Copyright?2011John Wiley&Sons,Ltd.Lubrication Science(2011)

DOI:10.1002/ls

ADDITIVES ON AISI52100STEEL/AL2O3CERAMICS

Wear mechanism.Since the measurable wear occurs only on the steel ball owing to the great difference in hardness between the mated materials,only the wear mechanism of the steel ball is analysed in this paper.

Figure5presents the SEM images of the worn surfaces of52100steel balls at200N.As shown in Figure5a,obvious ploughed grooves and lots of shallow?aking are observed on the worn surface under the base oil containing1wt%T451.With the percentage of T451up to3wt%,a smaller quantity of shallow?aking and slighter ploughed grooves turn to be the dominant wear mode.Figure5d shows, under the base oil containing1wt%T451+1wt%KT5447,that the worn surface is smoother compared with that under T451alone;with the percentage of KT5447up to2wt%,the combination of T451 and KT5447leads to slighter ploughed grooves and less shallow spalling(Figure5e).As shown in Figure5g and5h,slight ploughed grooves and pitting are on the worn surfaces of the steel ball under 2wt%T451+1wt%KT5447,whereas some ploughed grooves and shallow spalling are on the worn surface under2wt%T451+3wt%KT5447.There are some shallow ploughed grooves on the steel ball worn surface under3wt%T451+1wt%KT5447and3wt%T451+3wt%KT5447.

It is well known that the lubricant additives such as the sulphur compound,the phosphorus compound,the chlorine compound and the high‐effective multifunctional oil additive containing S,P and N and others have been widely used,in order that a tribochemical reaction?lm can form on the steel worn surface.Meanwhile,the modern surface analysis showed that the tribochemical products

the

are the compounds containing Fe and S,P or Cl(such as FeS,FeSO4or FePO4),which have Array

Figure6.Photoelectron spectroscopy survey(a)and high‐resolution spectra of S2p(b)and P2p(c)of the

steel balls at200N.

Copyright?2011John Wiley&Sons,Ltd.Lubrication Science(2011)

DOI:10.1002/ls

S.JIANG AND H.XIE

properties of the low melting point and the low shearing strength,resulting in reducing the friction coef?cient and wear rate of the pair.To provide further information about the formation of chemical species in the tribo?lms,an XPS spectrum of the worn scar of the steel ball at200N was taken with special regards for sulphur and phosphorus,as shown in Figure6.Under the three tested lubrication systems,Fe2p peak,O1s peak,C1s peak and Al2s peak can be seen.However,according to the high‐resolution spectra of S2p and P2p,no evidence is found for the formation of the expected sulphur‐containing or phosphorus‐containing chemical compound in the XPS spectrum results.

At400N

Friction coef?cient.The effect of the combination of T451and KT5447on the friction coef?cient of 52100/Al2O3at400N is shown in Figure7.The friction coef?cient under the base oil500SN alone increases obviously within the entire test duration;furthermore,as the sliding time is beyond25min,a steep increase in friction coef?cient will appear.A possible explanation is that a larger applied normal load would produce a greater heat generation;consequently,the higher interfacial temperature would speed up the rupture of the physical adsorption oil?lm formed on the steel ball surface.

It was also noticed that under the single KT5447,the friction coef?cients decrease to a low value of about0.11,indicating that the KT5447is appropriate for AISI52100steel/Al2O3ceramic.It can be

than

seen that the friction coef?cients under the compound of T451and KT5447are generally lower Array Figure7.Friction coef?cient at the load of400N under different lubrication systems. Copyright?2011John Wiley&Sons,Ltd.Lubrication Science(2011)

DOI:10.1002/ls

ADDITIVES ON AISI52100STEEL/AL2O3CERAMICS

those under KT5447alone.In conclusion,the combination of T451and KT54473has a signi?cant synergistic friction‐reducing effect for the52100/Al2O3at400N.

Wear rate.The comparison of WSDs of the steel balls under different lubrication systems at400N is shown in Figure8.Under the base oil,the WSD of the steel ball reaches1.62mm.The base oil containing the single KT5447can decrease wear rates of steel balls dramatically;the wear rate of the ball decreases with KT5447changed from1to2wt%and then increases with KT5447from2to3wt%. Under the compound of T451and KT5447,the wear rates of the steel balls are lower than those under KT5447alone,showing that the base oil containing KT5447and T451has the signi?cant synergistic AW effect for the52100/Al2O3at400N.

Wear mechanism.Figure9shows the SEM images of the worn surfaces of52100steel balls at the load of400N.The results show that abrasion is still the main wear mode at this load.In general,under the base oil containing1wt%KT5447or3wt%KT5447alone,the obvious ploughed grooves

and Array Figure8.Scanning electron microscope images of the worn surfaces of steel ball(applied load,400N; lubricant containing(a)1wt%KT5447,(b)2wt%KT5447,(c)3wt%KT5447,(d)1wt%KT5447+1wt% T541,(e)1wt%KT5447+3wt%T541,(f)2wt%KT5447+1wt%T451,(g)2wt%KT5447+2wt%T451, (h)2wt%KT5447+3wt%T451,(i)3wt%KT5447+1wt%T451,(j)3wt%KT5447+2wt%T451and(k)

3wt%KT5447+3wt%T451).

Copyright?2011John Wiley&Sons,Ltd.Lubrication Science(2011)

DOI:10.1002/ls

S.JIANG AND H.XIE

Figure9.Scanning electron microscope images of the worn surfaces of steel ball(applied load,400N;lubricant containing(a)1wt%KT5447,(b)2wt%KT5447,(c)3wt%KT5447,(d)1wt%KT5447+1wt%T541,(e) 1wt%KT5447+3wt%T541,(f)2wt%KT5447+1wt%T451,(g)2wt%KT5447+2wt%T451,(h)2wt% KT5447+3wt%T451,(i)3wt%KT5447+1wt%T451,(j)3wt%KT5447+2wt%T451and(k)3wt%

KT5447+3wt%T451).

Copyright?2011John Wiley&Sons,Ltd.Lubrication Science(2011)

DOI:10.1002/ls

ADDITIVES ON AISI52100STEEL/AL2O3CERAMICS

spalling are observed on the worn surface of the steel ball worn surface(as shown in Figure9a and9c. However,the worn surface of the ball under2wt%KT5447is smooth with less shallow ploughed grooves,which coincides with the fact that the base oil containing2wt%KT5447has the lowest friction coef?cient and wear rate.Figure9d and9e shows that under the base oil containing1wt% KT5447+3wt%T451,less ploughed grooves and shallow spalling are found on the steel worn surface compared with that under1wt%KT5447+1wt%T451;furthermore,1wt%KT5447blended with T451in all percentages leads to smoother surfaces than that under1wt%KT5447alone.Under the base oil containing2wt%KT5447+1wt%T451,dense pitting and shallow spalling are observed (Figure9f),whereas corrosion pitting and spalling are found on the steel worn surface under2wt% KT5447+3wt%T451.The base oil containing2wt%KT5447+2wt%T451leads to smoother surface than those under2wt%KT5447+1wt%T451and2wt%KT5447+3wt%T451.The possible explanation is that the smoother steel ball worn surface is of bene?t to the decrease of the friction coef?cient and wear rate,which coincides with the above test results.

The worn surfaces of the steel balls under3wt%KT5447+1wt%T451and3wt%KT5447+2wt% T451are characterised by obvious corrosion,pitting,spalling and ploughed grooves;with the percentage of T451up to3wt%,the steel worn surface turns out to be smoother.

X‐ray photoelectron spectroscopy analysis of the worn steel ball surface was also taken,as shown in Figure10.At400N,Fe2p peak,O1s peak,C1s peak and Al2s peak are also seen under the three tested lubrication systems.However,the high‐resolution spectra of S2p and P2p indicate that no evidence can prove the formation of the expected sulphur‐containing or phosphorus‐containing chemical compound.

Figure10.Photoelectron spectroscopy survey(a)and high‐resolution spectra of S2p(b)and P2p(c)of the

steel ball at400N.

Copyright?2011John Wiley&Sons,Ltd.Lubrication Science(2011)

DOI:10.1002/ls

S.JIANG AND H.XIE

The study indicates that the base oil containing T451and KT5447appears to have the effective friction‐reducing and AW effect for the AISI52100steel/Al2O3ceramics.Unfortunately,XPS analysis results of the worn steel ball surfaces cannot understand the cause of the synergistic effect;the author will focus on this problem in the near future.By the way,in the previous tribotest of the ceramic/steel,it often occurred that no S2p or P2p compound can be detected on the steel wear surface, although the pair reveals the signi?cant friction‐reducing and AW effect.20–22The author think this can be attributed to the fact that alumina is a porous material and its hardness is much higher than that of the AISI52100steel;under the maximum Hertzian contact pressure over2.0GPa in this test,the thin sulphur‐containing or phosphorus‐containing tribochemical protective?lm on the steel ball worn surfaces can be easily scraped or ruptured from the rubbing or microcutting action by the hard alumina ceramic disc during the shut‐down period of the tribometer.It should be mentioned that after the tribotest,the small hollows on the alumina disc are?lled with the abrasive grains of the steel surface.

CONCLUSION

?For the light load of200N,the base oil containing T451and KT5447appears to have synergistic friction‐reducing and AW effect on AISI52100steel/Al2O3ceramic.Under the single T451,the friction coef?cient and the wear rate of the pair decrease monotonously with the increasing of adding amount.Under the combination of T451and KT5447,3wt%T451+2–3wt%KT5447 shows the best friction‐reducing and AW effect on AISI52100steel/Al2O3ceramic.

?For the high load of400N,the single KT5447can decrease the friction coef?cient and the wear rate,and2wt%KT5447is more effective than1wt%KT5447and3wt%KT5447.The combination of T451and KT5447also appears synergistic friction‐reducing and AW effect on AISI52100steel/Al2O3ceramic.

?The ploughed grooves,pitting,spalling and corrosion are the dominant wear modes of the pair for both the light load of200N and the high load of400N.XPS analysis results show that no S2p or P2p can be detected to prove the formation of the expected sulphur‐containing or phosphorus‐containing chemical compound on the steel ball worn surfaces at both the light and heavy loads.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the support of the National Science Foundation through grant nos5047507and 50775036,Ministry of Science and Technology Project through grant nos2009zx04‐021and2009zx02011‐003and Jiangsu Science and Technology Project through grant nos BG2006035and BK2009612.

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DOI:10.1002/ls

陶瓷基摩擦材料的研究

陶瓷基摩擦材料的研究 白克江 (东营信义汽车配件有限公司山东东营257335) 摘要:本文通过对陶瓷基摩擦材料摩擦原理的探讨,分析了陶瓷配方的优异性,明确了摩擦性能调节剂在陶瓷配方中的重要作用,并利用国际先进的试验方法FMVSS135对配方性能进行了全面的研究。 关键词:陶瓷基摩擦材料摩擦性能调节剂 Abstract:The article analyzes the excellent of ceramics formula and makes clear the importance of friction regulator in ceramic formula by studying the principle of ceramic radicle and completely researching the formula function through the international advanced trial method FMVSS135. Keywords:Friction material of ceramic radicle Friction function regulator 一、前言 做为刹车片的摩擦材料,在满足人们正常使用中制动性能的同时,其使用寿命、环保性和舒适性也是人们非常关注的一个问题。而影响其使用寿命、环保性和舒适性的关键因素便是摩擦材料中基础增强材料和摩擦性能调节剂的选择和正确应用。 众所周知,石棉在摩擦材料中具有优秀的综合性能,但石棉有害健康,而且其在我国已经逐渐开始被禁用。半金属摩擦材料虽然因其比较优异的性能已经得到了广大用户的认可,但其易锈蚀、伤对偶、易发生噪音的缺点,一直在困惑着摩擦材料的研究者们,因此随着摩擦材料的发展,少金属和非金属摩擦材料应运而生,本文探讨的便是NAO摩擦材料中的一种:陶瓷基摩擦材料。 陶瓷基摩擦材料是一种利用无机矿物纤维和有机纤维做为增强材料,以改性树脂和橡胶粉为粘合剂,利用多种有机和无机材料做为摩擦性能调节剂配合加工而成的摩擦材料。其特点是无噪音、落灰少,不伤对偶、使用寿命长、无锈蚀。 二、基础摩擦材料的选择 1、增强纤维的选择 矿物纤维和陶瓷纤维的使用温度均可达到1000℃以上,具有良好的分散性能及高温稳定性,且价格比较便宜。这两种纤维的长径比比较小,虽然具有较大的比表面积,但其增强效果并不是十分的理想,因此本研究选用矿物纤维、陶瓷纤维及凯芙拉进行三元复合,来改善摩擦材料的高温摩擦性能和机械强度,以满

氧化铝陶瓷的制备与应用

论文题目:氧化铝陶瓷的制备与应用 学院:材料科学与工程学院 专业班级:材料化学2班 学号:20090488 姓名:王杰 日期:2011-10-19

氧化铝陶瓷的制备与应用 摘要:氧化铝陶瓷是用途最广泛的陶瓷材料中的一种,它可用作机器及设备制造中的耐腐蚀材料、化工专业中的抗腐蚀材料、电工及电子技术中的绝缘材料、热工技术中的耐高温材料以及航空、国防等领域中的某些特种材料。 Abstract: the alumina ceramics is the most widely use of one of the ceramic material, it can be used as the machine and equipment manufacture of corrosion resistant material, chemical corrosion materials in the professional, electrical and electronic technology of thermal insulation materials, high temperature resistant materials and technologies in the aerospace, defense, etc to some of the special material. 关键词:氧化铝陶瓷耐磨性机械强度耐化学腐蚀 Keywords: alumina ceramics Wear resistance Mechanical strength Chemical corrosion-resistant 氧化铝陶瓷是一种用途广泛的陶瓷。因为其优越的性能,在现代社会的应用已经越来越广泛,满足于日用和特殊性能的需要。[1] 1.硬度大经中科院上海硅酸盐研究所测定,其洛氏硬度为HRA80-90,硬度仅次于金刚石,远远超过耐磨钢和不锈钢的耐磨性能。 2.耐磨性能极好经中南大学粉末冶金研究所测定,其耐磨性相当于锰钢的266倍,高铬铸铁的171.5倍。根据我们十几年来的客户跟踪调查,在同等工况下,可至少延长设备使用寿命十倍以上。

烧结金属摩擦材料现状与发展动态

烧结金属摩擦材料现状与发展动态 newmaker 1 前言 烧结金属摩擦材料是以金属及其合金为基体,添加摩擦组元和润滑组元,用粉末冶金技术制成的复合材料,是摩擦式离合器与制动器的关键组件。它具有足够的强度,合适而稳定的摩擦系数,工作平稳可靠,耐磨及污染少等优点,是现代摩擦材料家族中应用面最大、量最大的材料。 用粉末冶金技术制造烧结金属摩擦材料已有70年的历史,1929年美国开始了这项工作的研究,30年代末期首先将该材料用在了D-7、D-8铲运机中的离合器片上。发展到现在,所有载荷量高的飞机,包括米格、伊尔、波音707、747和三叉戟等,其制动器摩擦衬材料都采用了烧结金属摩擦材料。在我国,特别是在1965年以后,烧结金属摩擦材料的科研、生产得到迅速发展。迄今,我国已有十多个具有一定生产规模的生产企业,年产铜基和铁基摩擦制品约850万件,广泛应用于飞机、船舶、工程机械、农业机械、重型车辆等领域,基本满足了国内主机配套和引进设备摩擦片的备件供给和使用要求。 2 制造方法与工艺研究 2.1 制造方法 目前,国内外烧结金属摩擦材料的生产仍主要沿用1937年美国S·K·Wellman及其同事们创造的钟罩炉加压烧结法(压烧法),该方法的基本工序是:钢背板加工→往油、电镀铜层(或铜、锡层);配方料混合→压制成薄片→与钢背板烧结成一体→加工沟槽及平面。由于传统的压烧法存在着能耗大、生产效率相对低、原材料粉末利用率低、本钱高等缺点。因此,一些国家对传统工艺作了一些改进,同时十分注重新工艺的研究,在改善或保证产品性能条件下探索和寻求进步经济效益的途径。 新的制造工艺相继问世,其中最令人瞩目的是喷撒工艺(Sprinkling powder procedure),它以生产的高效率和明显的经济效益独具上风。喷撒工艺法以产业规模生产烧结金属摩擦材料始于70年代,美国的威尔曼、西德的奥林豪斯和尤里特、奥地利的米巴等企业拥有这项技术。80年代中期,杭州粉末冶金研究所从奥地利米巴公司引进了该技术。 喷撒工艺的基本流程是:钢背板在溶剂(如四氯化碳中脱脂处理(或钢背板电镀)→在钢背板上喷撒上混合材料→预烧→压沟槽→终烧→精整。 与传统的压烧法相比,喷撒工艺主要有下列一些优点: (1)实现了无加压连续烧结,耗能低。

多孔氧化铝陶瓷的研究进展

多孔氧化铝陶瓷的研究进展 李环亭1 孙晓红1 陈志伟1,2 (1国家陶瓷与耐火材料产品质量监督检验国家质检中心 山东淄博 255063) (2山东理工大学分析测试中心 山东淄博 255049) 摘 要 综合论述了国内外多孔氧化铝陶瓷的制备方法及性能的研究进展,并对目前存在的问题及将来的研究方向进行了展望。 关键词 多孔氧化铝陶瓷 制备方法 性能 Research Progress of Porous A lumina Ceramics Li Huanting1,Sun Xiaohon g1,Chen Zhiwei1,2(1National Quality Supervision and Inspection Center for Ceramics and Refractories,Shan dong,Zibo,255063)(2Analysis and Testing Center of Shandong Uni versity of Technology,Shandong,Zibo,255049) Abstract:The paper reviewed the research progress of porous alumina ceramics home and broad.The preparation methods and the proer ties were summaried.Finally,the research direction in the future is given on the porous alumina ceramics. Key words:Porous alu mina ceramics;Preparation methods;Properties 前言 多孔氧化铝陶瓷是指以氧化铝为骨料,通过在材料成形与高温烧结过程中,内部形成大量彼此相通或闭合的微孔或孔洞。较高的孔隙率的特性,使其对液体和气体介质具有有选择的透过性,较低的热传导性能,再加上陶瓷材料固有的耐高温、抗腐蚀、高的化学稳定性的特点,使其在气体和液体过滤、净化分离、化工催化载体、生物植入材料、吸声减震和传感器材料等众多领域有着广泛的应用前景。多孔氧化铝陶瓷上述优异的性能和低廉的制造成本,引起了科学界的高度关注。笔者就目前国内外多孔氧化铝陶瓷的制备方法、性能的研究进展进行综述。 1 多孔氧化铝陶瓷的制备方法 多孔氧化铝陶瓷的制备工艺主要包括孔结构的形成,坯体的成形和坯体的烧结3个方面。关于孔结构形成的方法既有传统的通过机械挤出成孔法、颗粒堆积形成气孔法、添加造孔剂成孔法、发泡工艺成孔法、有机泡沫浸渍成孔法[1],也有新型的铝板阳极氧化法、溶胶-凝胶法等。关于坯体成形工艺主要有模压成形法[2]、凝胶注模成形法[3]、固体粒子烧结法[4]、挤压成形法[5]等。如何得到高的气孔率,且能较好地控制孔径及其分布、形状、三维排列等,则需要选择合适的方法和工艺。下面介绍几种氧化铝多孔陶瓷常用的制备方法。 1.1 造孔剂成孔+凝胶注模法+高温烧结法 造孔剂成孔法是将一定量的造孔剂添加到陶瓷坯料中,造孔剂在坯体中会占据一定的空间,经过低温烧结后,造孔剂离开基体形成气孔得到多孔陶瓷。造孔剂的种类分为有无机和有机两大类。无机造孔剂有碳酸铵、碳酸氢铵、氯化铵等高温可分解的盐类,以及煤粉、碳粉等;有机造孔剂主要是天然纤维、高分子聚合物[6]和有机酸等,如淀粉、尼龙纤维等。目前应用较多的是加入有机造孔剂,且效果较好。由于造孔剂颗粒的大小及形状决定最终成孔的大小和形状,且造孔剂 基金项目:山东省科技攻关项目(耐火材料快速分析方法研究及应用,项目编号:2006GG1108097-06;陶瓷原料综合评价方法建立及应用研究,项目编号2007GG10003047)

金属硫化物陶瓷摩擦材料的制备与性能研究_李双君

金属硫化物陶瓷摩擦材料的制备与性能研究 李双君,魏明坤 (武汉理工大学理学院,湖北武汉430070) 摘要:以硫粉、锡粉、三硫化二锑为烧结剂,再加入其他辅助原料,利用金属硫化物的低熔点烧结制备陶瓷摩擦材料。研究了原料的不同配比对金属硫化物陶瓷摩擦材料的体积密度、气孔率、力学性能、摩擦性能以及显微结构的影响。硫含量对金属硫化物陶瓷摩擦材料性能有很重要的影响,通过对比寻求较为理想的原料配比,并对其实际应用的可行性进行探讨。 关键词:硫化物陶瓷;摩擦材料;性能 Preparati on ofM etal Sulfi des Cera m i c Friction M aterial and its Properties LI Shuang-jun,WE I M ing-kun (Schoo l o f Sc i e nce,W uhan Un iversity of Techno l o gy,H ube iW uhan430070,Chi n a) Abst ract:E le m ental su lfur,ti n powder and anti m ony trisu lfide used as sinteri n g agents,and then added other sup-porti n g m aterials,w ith lo w m elti n g po i n tm etal su lfides sinteri n g,cera m ic fricti o n m ater i a lw as prepared.The ra w m ater-i als of different proporti o ns ofm etal su lfide cera m ic friction m ateria l b u l k density,porosity,m echanical properties,friction properties and m icr oscopic structure w ere studied.Su lfur content had a sign ificant i m pact on m eta l sulfi d e cera m ic friction m aterial perfor m ance,By co m pari n g the ratio o f ra w m ateria ls,a m ore satisfactory rati o of ra w m aterials w as found ou,t and the feasi b ility of the ir practical app lication w as discussed. K ey w ords:su lfi d e cera m ic;friction m ateria;l property 车载摩擦片发展到现在,大概分为四种类型:石棉基摩擦衬片、半金属摩擦制动衬片、无石棉摩擦制动衬片和金属基烧结摩擦制动衬片[1]。 石棉基摩擦材料因为有致癌作用已遭淘汰。半金属摩擦材料中钢纤维容易生锈,锈蚀后易出现粘着对偶或者损伤对偶,使摩擦片强度降低,磨损加剧,摩擦系数稳定性变差;当摩擦温度高于300e时,易出现剥落现象,密封圈软化和制动液发生气化而造成制动失灵;易产生低速下的低频噪音。金属基摩擦材料磨损率高、摩擦传载力矩低、高温下性能衰退严重等,难以适用在重载干式离合器中[2]。 目前,虽然很多无石棉摩擦材料的综合性能已得到进一步提高,但仍存在很多问题,如有的材料在性能提高的同时,成本也大幅度提高,有的材料则出现粘结强度不够、噪声大等问题,所以全面提高新型摩擦材料的性能仍是亟待解决的一项任务。 本课题利用硫化锡、三硫化二锑的熔点较低,以其为烧结剂,添加其它助剂在较低的温度下烧结制备金属硫化物陶瓷摩擦材料,有利于降低能耗及生产成本,使其具有良好的摩擦性能,有良好的应用前景。并研究了不同配比的原料对金属硫化物陶瓷性能的影响。 1实验部分 1.1试样制备 金属硫化物陶瓷材料的配比见表1。 表1金属硫化物陶瓷材料的配比(w t%) 试样编号升华硫锡粉三硫化二锑铁铝粉钢钎氧化铝粉石墨二硫化钼100253530532 213213530532 325183530532 437153530532 549123530532 651193530532 1.2实验过程 按照表1所示配方配料,然后进行球磨搅拌混料,将配好的原料装入模具中,在压力320M P a用粉末压样机压制成型,于可控硅高温炉中常压烧结,温度500e。保温2h后自然冷却,再将 # 101 # 2010年38卷第6期广州化工

摩擦材料

摩擦材料 一、概论 摩擦材料是一种应用在动力机械上,依靠摩擦作用来执行制动和传动功能的部件材料。它主要包括制动器衬片(刹车片)和离合器面片(离合器片)。刹车片用于制动,离合器片用于传动。 任何机械设备与运动的各种车辆都必须要有制动或传动装置。摩擦材料是这种制动或传动装置上的关键性部件。它最主要的功能是通过摩擦来吸收或传递动力。如离合器片传递动力,制动片吸收动能。它们使机械设备与各种机动车辆能够安全可靠地工作。所以说摩擦材料是一种应用广泛又甚关键地材料。 摩擦材料是一种高分子三元复合材料,是物理与化学复合体。它是由高分子粘结剂(树脂与橡胶)、增强纤维和摩擦性能调节剂三大类组成及其它配合剂构成,经一系列生产加工而制成的制品。摩擦材料的特点是具有良好的摩擦系数和耐磨损性能,同时具有一定的耐热性和机械强度,能满足车辆或机械的传动与制动的性能要求。它们被广泛应用在汽车、火车、飞机、石油钻机等各类工程机械设备上。民用品如自行车、洗衣机等作为动力的传递或制动减速用不可缺少的材料。 二、摩擦材料发展简史 自世界上出现动力机械和机动车辆后,在其传动和制动机构中就使用摩擦片。初期的摩擦片系用棉花、棉布、皮革等作为基材,如:将棉花纤维或其织品浸渍橡胶浆液后,进行加工成型制成刹车片或刹车带。其缺点:耐热性较差,当摩擦面温度超过120℃后,棉花和棉布会逐渐焦化甚至燃烧。随着车辆速度和载重的增加,其制动温度也相应提高,这类摩擦材料已经不能满足使用要求。人们开始寻求耐热性好的、新的摩擦材料类型,石棉摩擦材料由此诞生。 石棉是一种天然的矿物纤维,它具有较高的耐热性和机械强度,还具有较长的纤维长度、很好的散热性,柔软性和浸渍性也很好,可以进行纺织加工制成石棉布或石棉带并浸渍粘结剂。石棉短纤维和其布、带织品都可以作为摩擦材料的基材。更由于其具有较低的价格(性价比),所以很快就取代了棉花与棉布而成为摩擦材料中的主要基材料。1905年石棉刹车带开始被应用,其制品的摩擦性能和使用寿命、耐热性和机械强度均有较大的提高。1918年开始,人们用石棉短纤维与沥青混合制成模压刹车片。20世纪20年代初酚醛树脂开始工业化应用,由于其耐热性明显高于橡胶,所以很快就取代了橡胶,而成为摩擦材料中主要的粘结剂材料。由于酚醛树脂与其他的各种耐热型的合成树脂相比价格较低,故从那时起,石棉-酚醛型摩擦材料被世界各国广泛使用至今。 20世纪60年代,人们逐渐认识到石棉对人体健康有一定的危险性。在开采或生产过程中,微细的石棉纤维易飞扬在空气中被人吸入肺部,长期间处于这种环境下的人们比较容易患上石棉肺一类的疾病。因此人们开始寻求能取代石棉的其它纤维材料来制造摩擦材料,即无石棉摩擦材料或非石棉摩擦材料。20世纪70年代,以钢纤维为主要代替材料的半金属材料在国外被首先采用。80年代-90年代初,半金属摩擦材料已占据了整个汽车用盘式片领域。20世纪90年代后期以来,NAO(少金属)摩擦材料在欧洲的出现是一个发展的趋势。无石棉,采用两种或两种以上纤维(以无机纤维为主,并有少量有机纤维)只含少量钢纤维、铁粉。NAO(少金属)型摩擦材料有助于克服半金属型摩擦材料固有的高比重、易生锈、易产生制动噪音、伤对偶(盘、鼓)及导热系数过大等缺陷。目前,NAO (少金属)型摩擦材料已得到广泛应用,取代半金属型摩擦材料。2004年开始,随汽车工业飞速发展,人们对制动性能要求越来越高,开始研发陶瓷型摩擦材料。陶瓷型摩擦材料主要以无机纤维和几种有机纤维混杂组成,无石棉,无金属。其特点为: 1. 无石棉符合环保要求; 2. 无金属和多孔性材料的使用可降低制品密度,有利于减少损伤制动盘(鼓)和产生制动噪音的粘度。 3. 摩擦材料不生锈,不腐蚀; 4. 磨耗低,粉尘少(轮毂)。 三、摩擦材料分类 在大多数情况下,摩擦材料都是同各种金属对偶起摩擦的。一般公认,在干摩擦条件下,同对偶摩擦系数大于0.2的材料,称为摩擦材料。 材料按其摩擦特性分为低摩擦系数材料和高摩擦系数材料。低摩擦系数材料又称减摩材料或润滑材料,其作用是减少机械运动中的动力损耗,降低机械部件磨损,延长使用寿命。高摩擦系数材料又称摩阻材料(称为摩擦材料)。

氧化铝陶瓷与金属连接的研究现状

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周健等Ⅲo对A1203一A1203以及A1203和HAP(羟基磷灰石)生物陶瓷进行了焊接,并借助电镜、电子探针分析了界面结合情况。前者在2MPa、1300℃、保温15min时结合强度达到基体强度。后者在2.5MPa、1200℃、保温15min左右将两类材料焊接在一起。. 蔡杰等¨引采用1’E103型谐振腔分别在1300和1400℃对A1203一A1203进行焊接,认为在1300℃焊接时,虽经长时间保温,焊接效果不理想,在1400℃、保温20min,焊缝消失。如上所述,氧化铝陶瓷一般采用直接焊接,对于高纯度氧化铝陶瓷一般采用低纯氧化铝或玻璃做中间层,目前也有人用溶胶凝胶方法制备的氧化铝做中间层。 目前微波焊接腔体的微波场的均匀区域还不大,改进微波场的分布,提高加热均匀区域,可以提高材料的焊接尺寸。同时增加焊接材料的种类。 7激光焊接 激光焊接陶瓷是近年来发展的新技术,Mittweida公司开发了双束激光焊接陶瓷方法,其原理见图9。 图9双束激光焊接示意图¨引 Fig.9Skd【chofdoublelaserweldiIlg 采用高能束激光焊方法,可快速加热和冷却,配以氮气筛的冷却和温度场调节,诱导和改善复合材料增强相和基体界面反应,而提高接头强度。采用脉冲输入方式,可抑制界面反应,细化组织,减少缺陷,获得良好接头,在操作时对激光功率控制非常重要啪J。用该法焊接的Al:O,陶瓷试样,激光焊接区细晶粒均匀,在电子显微镜下,可以看到晶粒呈片瓦结构,防止了裂纹的产生和扩展。经100次反复加热和冷却后,试样的弯曲强度无明显下降。 8结语 随着Al,O,陶瓷的广泛应用,其连接技术已成为世界各国集中研究的重点,其中钎焊与扩散连接是最常用的连接方法,但都有其局限性。例如:用钎焊方法形成的陶瓷接头的高温性能和抗氧化性能较差;钎焊的界面反应机理现在还处于试验阶段,缺乏系统性和理论性。扩散连接虽然可以减小界面缺陷,并适合大尺寸构件的接合,但易发生试件的变形和损伤等。近来新发展的微波连接能很好地实现接头处均匀连接,避免了开裂的发生,而且由于升温速度极快,陶瓷内部的晶粒不会剧烈长大。而sHs焊接和激光焊接还处于起步阶段,有待于发展。 参考文献 1王颖.AJ:0,陶瓷与Kover合金钎焊工艺研究.哈尔滨工业大学硕士论文,2006:l一50 2Ham咖dJP,DB“dSA,SameUaMLB阳zingo既帅icox-id船tom吨IlsatlowteⅡ聊舶hlr酷.WeldJ,1992;(5):145—1493赵永清.利用化学镀实现A120,陶瓷与金属的连接.焊接技术,1999;(2):16—17 4顾小龙,王大勇,王颖.Al:0,陶瓷/AgCuT∥可伐合金钎焊接头力学性能.材料科学与艺,2007;15(3):366—3695吴铭方.反应层厚度对他03/AgCu7n/n一6m一4V接头强度的影响.稀有金属材料与工程,2000;19(26):419—4226王洪潇.氧化铝陶瓷与金属活性封接技术研究.大连交通大学硕士论文,2006:1—50 7刘军红.复相Al:0,基陶瓷/钢大气中直接钎焊连接界面的微观组织结构.焊接学报,2003;24(6):26—28 8张玮.镍离子注入灿203/1crl8Ni9Ti的钎焊界面成分分析.包头钢铁学院学报,2000;19(3):219—22l 9王大勇,冯吉才,刘会杰.灿:O,/Cu/Al扩散连接工艺参数的优化.材料科学与工艺,2003;11(1):73~76 10陈铮,赵其章,方芳等.陶瓷/陶瓷(金属)部分瞬间液相连接.硅酸盐学报,1999;27(2):186~188 1lMerzh锄ovAG.InterSymposium∞coIIIbus阴dpl嬲一眦syn.ofhigll—te呷.Mater.s明Fr锄cisco,cA,988 12余圣甫等.Al:0,陶瓷/不锈钢自蔓延高温原位合成连接.焊接学报,2004;25(2)119一122 13周健,章桥新,刘桂珍等.微波焊接陶瓷辊棒.武汉工业大学学报,1999;21(3):1~2 14MeekTT,BlalceRD.Ceramic?ce硼icsealsbymicro-w盯ehe砒ing.J.Mat.Sci.L肚.,1986;(5):270~274 15Fukushi眦H。YamanakaT,Ma协uiM.Micmwaveheat—ingof ce姗icsandi协applic砒i叩tojoining.JMat.R∞.,1990;5(2):397—405 16Bi衄erJGP,F唧ieJA,WhitakerPAeta1.Thee妇fect0fcompositi∞ontlIeIIlicn)wavebondirIg0falulIli啪ce捌【nics.JMat.sci.,1998;33(12):3017~3029 17zlI伽Ji蛐,Zh衄gQia喇n,MEIBingchueta1.Mic胁wavejoiIlingof aluIIli腿c廿枷candh”Iroxyl印atitebioce枷c.JWuh粕Univ.ofTech.Mater.Sci.,1999;14(2):46~4918ChenXinm伽,ⅡuW嘶.HigllFrequencyHeatillgDie.1ectricTechnology.BeijiIlg:scie眦ePr鹤s,1979:l一30 19C蛐G,K0caI【M.h咿ssinjoiniIlgofadv锄cedmate—rials.htematioIlalMaterialsRevie啪,1998;43(1):卜4420广赖明夫.金属基复合材料。结合.溶接会志,1996;65(4):l692一l698 (编辑吴坚) 宇航材料工艺2008年第4期 万方数据

氧化铝陶瓷制作工艺

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—21— 新材料新装饰XINCAILIAOXINZHUANGSHI 2014年4期 汽车离合器用铜基金属 陶瓷摩擦材料的研究进展 冯超 徐吉波 魏子良 王琦 胡欢 (湖北汽车工业学院 材料科学与工程学院 十堰湖北 442002) 摘要:金属陶瓷摩擦材料具有吸能效率高、导热性好、摩擦系数高、耐高温、耐磨等特点,可用 于重型车、矿区用车、工程作业车、沙漠车等重载荷车辆以代替不抗热的有机摩擦片。本文综述了铜基金属陶瓷摩擦材料的发展现状,展望了铜基金属陶瓷摩擦材料的发展前景。 关键词:金属陶瓷;铜基摩擦材料;研究进展 1前言 汽车离合器靠摩擦来传递动力。当汽车行驶时,离合器的主动部件和从动盘相互压紧而一起旋转,但在起步、换档过程中,主、从动件之间相对摩擦,从动盘摩擦片发热并发生磨损。离合器的使用寿命主要取决于其从动盘摩擦片的耐磨性。通常汽车离合器从动盘摩擦片采用树脂基石棉材料做成。在160℃以上树脂片自身及其对偶件的磨损量都急剧增大,而金属陶瓷片在250℃以上仍保持很好的耐磨性,其对偶的磨损也很小。另一方面,金属陶瓷摩擦材料对铸铁的摩擦系数要比树脂石棉片对铸铁的摩擦系数高一些,因此用金属陶瓷摩擦片的离合器在同一夹紧载荷下,能比采用树脂片的离合器提供更大的摩擦力矩,亦即在保证相同的扭矩容量下所用的夹紧载荷减小,从而使离合器接合更柔和,在相同夹紧力下扭矩得到提高[1,2]。 2 铜基金属陶瓷摩擦材料的应用 从20世纪50年代起,国外就在拖拉机、工程机械及载货汽车上开始使用金属陶瓷磨擦材料作为离合从动盘的磨擦面片。由于金属陶瓷磨擦面片的磨擦系数高于有机石棉片,采用金属陶瓷磨擦面片的离合器与采用石棉片的离合器相比,在同一夹紧载荷下可提供更大的磨擦力矩,即离合器扭矩容量较大;而在同样大小的扭矩容量下,所用夹紧载荷较小,使离合器接合更平稳、柔和。此外,金属陶瓷材料比有机材料更耐高温,对于起步换挡频繁、离合器工作温度较高的汽车来说,用金属陶瓷材料更耐磨。据有关资料介绍,在温度160℃以下有机片的耐磨性还是比较好,但当温度更高时,其耐磨性急剧下降;而金属陶瓷材料则在接近300℃的高温下仍有较好的耐磨性。显然,对于使用条件恶劣的车辆来说,其离合器从动盘磨擦面的工作温度高,只有用耐高温的金属陶瓷材料才能保证足够长的使用寿命。据有关资料介绍,采用金属陶瓷片的离合器使用寿命比有机片的长75%。 3 国内外研究现状 金属陶瓷磨擦材料是由金属基体、陶瓷成份和润滑剂组成的一种多元复合材料。金属基体的主要作用是以机械结合的方式将陶瓷成份和润滑剂保持于其中,形成具有一定机械强度的整体;陶瓷成份主要起磨擦剂作用;而润滑剂成份则主要起提高材料抗咬合性和抗粘接性的润滑作用,特别有利于降低对偶材料的磨损,并使磨擦副工作平稳。润滑剂组分和陶瓷组分共同形成金属陶瓷磨擦磨损性能的调节剂。基体作为摩擦材料的主要组元,其作用主要是以机械结合方式将摩擦颗粒和润滑剂保持于其中,形成具有一定力学性能的整体。基体的强度是摩擦材料承载能力的反应,在很大程度上取决于基体的成分、结构和物理一力学性能。目前改善材料基体结构和强度主要从两个方面入手[3-4]:一是添加合金元素来强化基体。二是在较软的基体中添加强度较高的金属纤维或其它增强纤维。基体的组织结构、物理化学性质 在很大程度上决定了粉末冶金摩擦材料的力学性能、摩擦磨损性能、 热稳定性和导热性等整体性能的发挥。摩擦材料要求基体具有足够高 的熔点,高的耐热强度和热稳定性,工作温度内有较高的塑性变形抗 力,高的耐磨性。开展对基体成分及性能的研究至关重要,对提高铜 基金属陶瓷摩擦材料摩擦性能提供有益的指导。 对铜基金属陶瓷摩擦材料基体的研究,不能仅局限于基体本身,因为现代高性能粉末冶金摩擦材料大多是多组元的复合体,各个组元对材料性能的作用是相互影响的,因此研究基体的同时也应考虑其它组元加入后对基体的影响。目前在基体方面的研究工作,大都是在摩擦材料三大组元都存在的情况下来研究的,主要涉及以下各个方面:基体的类型;基体的物理、机械性能对摩擦磨损性能的影响;合金元素(辅助组元)对基体性能的影响;基体组织、硬相和塑性相的分布、第二相的影响、摩擦过程中表层组织的变化;材料中非金属组分与金属基体的相互作用、基体夹持硬质点的能力、粘结问题的研究;改善基体的压制、烧结等工艺性能研究摩擦过程中表层元素扩散过程研 究;基体塑变能力对摩擦磨损性能的影响,孔隙度大小、分布对基体 性能的影响;改善基体耐热性、耐磨性的研究等诸多方面[5-6]。 4 发展现状 目前,随着重载汽车离合器片的发展,以及离合器结构设计的紧凑性要求,对铜基金属陶瓷摩擦材料的耐磨性和耐热性提出了更高要求,特别是高温制动的稳定性。因此研究开发具有优异性能的新型铜基摩擦材料十分重要和迫切。为提高铜基摩擦材料的耐热性和耐磨性,主要途径:添加合金元素来强化提高基体的耐磨性和耐热强度;通过改变材料的摩擦剂与润滑剂,调节材料的成分,如添加铁和石墨等耐高温、耐磨材料来提高摩擦材料的整体性能。目前铜基纳米复合材料的研究成果表明:纳米氧化物作为弥散增强相所制备的弥散强化铜基复合材料,在保持铜本身高导热性能的同时还大幅度提高了强度及抗高温软化特性,具有其他强化方法无法比拟的优点。因此,将纳米材料应用于铜基摩擦材料,为改善摩擦材料的摩擦学性能提供了新途径。 参考文献: [1]黄建龙,王建吉,党兴武,陈生圣.铝含量对铜基粉末冶金材料性能的影响.润滑与密封,2013,38(1):56-60. [2]邓海金,李明,龚敏.钢纤维对铜基金属陶瓷摩擦材料力学和摩擦学性能的影响.摩擦学报,2004,24(4):336-340. [3]钟志刚,邓海金,李明,等.铁含量对铜基金属陶瓷摩擦磨损性能的影响.材料工程,2002,(8):17-19. [4]王晔,燕青芝,张肖路,等.石墨对铜基粉末冶金闸片材料性能的影响.粉末冶金技术,2012,30(6):432-439. [5]Xiong X,Sheng H C,Chen J,et al.Effects of sintering pressure and temperature on microstructure and tribological characteristic of Cu-based aircraft brake material.Transactions of nonferrous metals society of China,2007,17:669 -675. [6]湛永钟,张国定,曾建民,等.SiC 和石墨混杂增强铜基复合材料的高温摩擦磨损特性研究.摩擦学学报,2006,26(3):223-227. 基金项目:湖北汽车工业学院大学生创新性实验项目基金资助。

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2007-04-04公布 2007-05-20实施 全国工业产品生产许可证办公室

目录 1总则 (1) 2工作机构 (2) 3企业取得生产许可证的基本条件 (3) 4许可程序 (4) 申请和受理.......................................................................................(4)企业实地核查....................................................................................(4)产品抽样与检验.................................................................................(5)审定和发证 (5)

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摩擦材料行业分析

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