外文翻譯--原位合成al2o3p增強鋁基復合材料的摩擦磨損性能（原文）

1、Trans. Nonferrous Met. Soc. China 24(2014) 2352?2358 Friction and wear properties of in-situ synthesized Al2O3 reinforced aluminum composites Xiao-song JIANG, Nai-juan WANG, De-gui ZHU School of Materials Science and En

2、gineering, Southwest Jiaotong University, Chengdu 610031, China Received 17 October 2013; accepted 29 April 2014 Abstract: Al?5%Si?Al2O3 composites were prepared by powder metallurgy and in-situ reactive synthesis techno

3、logy. Friction and wear properties of Al?5%Si?Al2O3 composites were studied using an M?2000 wear tester. The effects of load, sliding speed and long time continuous friction on friction and wear properties of Al?5%Si?A

4、l2O3 composites were investigated, respectively. Wear surface and wear mechanism of Al?5%Si?Al2O3 composites were studied by Quanta 200 FE-SEM. Results showed that with load increasing, wear loss and coefficient of fri

5、ction increased. With sliding speed going up, the surface temperature of sample made the rate of the producing of oxidation layer increase, while wear loss and coefficient of friction decreased. With the sliding distanc

6、e increasing, coefficient of friction increased because the adhesive wear mechanism occurred in the initial stage, then formation and destruction of the oxide layer on the surface of the sample tended to a dynamic equi

7、librium, the surface state of the sample was relatively stable and so did the coefficient of friction. The experiment shows that the main wear mechanism of Al?5%Si?Al2O3 composites includes abrasive wear, adhesive wear

8、 and oxidation wear. Key words: Al?5%Si?Al2O3 composites; friction and wear; coefficient of friction; load; sliding speed 1 Introduction Aluminum matrix composites (AMCs) play a significant role in metal matrix composit

9、es for their excellent properties, such as high specific strength and stiffness, good high temperature performance, resistance to fatigue and wear resistance, good damping property, low thermal expansion coefficient and

10、excellent mechanical properties [1?4]. Among feasible AMCs, the particle reinforced aluminum matrix composites are widely used in the automotive and generator industry owing to their light weight, unique wear resistance

11、and ease of preparation [5?7]. Recently, a number of researches on AMCs prepared by different methods were reported, especially about the wear properties. RAJMOHAN et al [8] concluded the mechanical and wear propert

12、ies of hybrid aluminium metal matrix composites fabricated by stir casting method. The relationship between mass fraction and wear properties of mica was observed in this work. KHORRAMIE et al [9] produced aluminum matri

13、x composites reinforced with Al2ZrO5 nano particulates by sol?gel auto- combustion method. The density, hardness and compression strength of the composites were discussed. ERARSLAN [10] researched the wear performan

14、ce of in-situ aluminum matrix composite after micro-arc oxidation. Compared with the original state, the wear resistance of the composites increased by about 15 times after treatment. Compared with above methods, hot iso

15、static pressing in-situ fabrication method is better due to its convenient to form homogeneous material directly. GAO et al [2] prepared Al?Si?Al2O3 composites by hot isostatic pressing method. Although microstructure an

16、d properties of in situ fabricated Al?5%Si?Al2O3 composites were studied by CHENG et al [11], the critical frication and wear properties of AMCs still remain to be studied. A12O3 is well known as the preferred reinf

17、orcement material. Moreover, Si is able to improve alloy liquidity, reduce the heat crack tendency and possess high hardness [1,12,13], which make it an attractive candidate for AMCs. If so, the wear resistance property

18、of the aluminum matrix material added with A12O3 and Si is better. So, we did the research in this Foundation item: Project (51201143) supported by the National Natural Science Foundation of China; Project (SWJTU12BR004)

19、 supported by the Fundamental Research Funds for the Central Universities, China Corresponding author: Xiao-song JIANG; Tel: +86-28-87600779; E-mail: xsjiang@yeah.net DOI: 10.1016/S1003-6326(14)63356-2 Xiao-song JIANG

20、, et al/Trans. Nonferrous Met. Soc. China 24(2014) 2352?2358 2354 Fig. 3 Relationship between abrasion loss and sliding distance under different loads Fig. 4 SEM images of Al?5%Si?Al2O3 composite samples under different

21、loads: (a) 30 N; (b) 50 N; (c) 80 N proportional with the increase of applied load [17]. In addition, DINAHARAN and MURUGAN [14] also proved that the wear rate increased linearly with the increase of normal load. Figu

22、re 3 reveals that the wear loss is stable and less volatile between 30 and 50 N. However, the amount of wear loss increases significantly under 80 N and wear resistance of the sample is affected seriously. Continuous

23、 wear grooves and some relatively shallow but homogeneous scratches are seen in Fig. 4(a) at 30 N. A few cracks are clearly visible at the edge of grooves. Compared with Fig. 4(a), the grooves and cavities in Figs. 4

24、(b) and (c) are deeper. At the same time, the proportion of cracks and delamination on the worn surface increases with the increase of load. In addition, the amount of wear loss increases gradually, so does the surf

25、ace roughness. The above factors make the friction coefficient larger. During sliding process, the mental flow was restricted in the presence of the secondary hard phases, such as Si and Al2O3 [18]. Simultaneously, S

26、i addition had a significant effect on the interface bonding strength in the Al/Al2O3 joints [1,19]. Playing the role of load bearer during the sliding process, the hard particles can reduce the effective contact are

27、a between the friction pairs, which reduced the material’s removal. When the soft base was worn under the external force, the particles would be exposed on the sample surface to bear the load mostly. It was conducive

28、 to prevent the soft matrix involved directly in the friction process. In addition, the inherent characteristic of in-situ fabrication method is able to produce a pure interface which improves the interfacial bonding

29、 strength [14]. Therefore, it is less likely for particles to strip from the substrate to exacerbate abrasive wear at low loads. As a result, the wear resistance of the composites was improved since its capacity resi

30、sted sticking and deformation [20,21]. At this moment, the dominant wear mechanism was abrasive wear which accompanied with mild oxidation wear and adhesive wear. During repeated wear process, particle fragmenta

31、tion occurred due to the formation of stress concentration and crack. As the third body, the wear debris formed under the high contact stress can damage the surface and cause detachment of oxides from surface of AMCs

32、 [22]. The higher the load was, the greater the extent of plastic deformation would be, which led to larger tribo-surface removal. Consequently, the contact area between the fiction pairs increased with load increasi

33、ng. It is responsible for the wear rate increasing. 3.2 Effect of sliding speed on friction and wear properties of Al?5%Si?Al2O3 composites Through the test, the effects of different sliding speeds on friction and wea