scholarly journals Effect of TiB content on the properties of Al-TiB composites

2018 ◽  
Vol 50 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Shen Yang ◽  
Zuoxing Guo ◽  
Maosheng Xia

In this study, titanium boride (TiB) was used to make Al-TiB composites. The contents of TiB added into Al matrix were 1 wt.%, 5 wt.% and 10 wt.%, respectively. The composites were pressed at a pressure of 382 MPa and sintered at 600?C for 4 hours. The microstructures and properties of density, hardness and wear were investigated. Experimental results indicated that, the composite with 5 wt.% TiB owned the highest relative density and hardness among the three parameters. In addition, TiB particles dramatically improved the wear resistance of the Al matrix and the more TiB content the better of the wear resistance. That is, the composite with 10 wt.% TiB owned the best wear resistance.

2014 ◽  
Vol 668-669 ◽  
pp. 52-55
Author(s):  
Yang Han ◽  
Ai Ling Zhang ◽  
Lin Yang ◽  
Ya Ling Han

The microstructure of 40CrNi2Mo steel matrix strengthened with wear resistance alloy is observed by the optical scope, SEM with EDS and FESEM. Analysis emphasis is lied on the distribution regulation of nanosized WC particulates in the microstructure of the steel matrix. Experimental results show that the method of adding wear resistance alloy in steel matrix can avoid gravity segregation phenomenon effectively and guarantee a uniform distribution of WC in steel matrix. nanosized WC particulates distributing evenly in steel matrix improve the wear resistance, and make microstructure of the steel matrix more uniform, finer and denser proved by its high-expansion micrograph.


Author(s):  
Yalcin Yuksel ◽  
Marcel van Gent ◽  
Esin Cevik ◽  
H. Alper Kaya ◽  
Irem Gumuscu ◽  
...  

The stability number for rubble mound breakwaters is a function of several parameters and depends on unit shape, placing method, slope angle, relative density, etc. In this study two different densities for cubes in breakwater armour layers were tested to determine the influence of the density on the stability. The experimental results show that the stability of high density blocks were found to be more stable and the damage initiation for high density blocks started at higher stability numbers compared to normal density cubes.


2016 ◽  
Vol 879 ◽  
pp. 1691-1697 ◽  
Author(s):  
Hisashi Sato ◽  
Junya Maeda ◽  
Motoko Yamada ◽  
Yoshimi Watanabe

As one of processing methods of functionally graded materials (FGMs), centrifugal mixed-powder method has been proposed. The centrifugal mixed-powder method is the casting process combined of centrifugal casting and powder metallurgy. This processing method has advantage that fine ceramics-particles, whose wettability with matrix melt is low, can be compounded into metallic material. However, effects of particle size on microstructure and mechanical properties of the FGMs fabricated by the centrifugal mixed-powder method are unclear. In this study, two kinds of Al-TiO2 FGMs rings are fabricated by the centrifugal mixed-powder method. One contains TiO2 particles having similar diameter with Al matrix particles (hereafter, small different-size (SD) TiO2 particles), and the other one compounds TiO2 particles with much smaller diameter than Al matrix particles (hereafter, large different-size (LD) TiO2 particles). In case of the Al-TiO2 FGMs ring containing SD-TiO2 particles, the TiO2 particles are homogeneously dispersed in Al matrix on outer surface of the ring. On the other hand, the TiO2 particles in the Al-TiO2 FGMs ring with LD-TiO2 particles are distributed along grain boundary of Al matrix. Moreover, Vickers-hardness and wear resistance around outer surface of the Al-TiO2 FGMs ring containing the SD-TiO2 particles is higher than that of the Al-TiO2 FGMs ring with LD-TiO2 particles. Since Al particles in the mixed-powder with LD-TiO2 particles are surrounded by the TiO2 particles, the Al particles can be hardly melted by heat of molten Al at casting process. As a result, the Al-TiO2 FGMs ring with LD-TiO2 particles has low hardness and wear resistance. Therefore, it is found that TiO2 particles having similar diameter with Al matrix particles are more suitable for fabrication of the Al-TiO2 FGMs rings.


1983 ◽  
Vol 27 ◽  
Author(s):  
P.B. Madakson

ABSTRACTCommercially pure Al was implanted with 300 keV Si+ and 200 keV Pb+ to doses of between l011 and 1017 ions/cm2. Changes in friction, wear, oxidation and hardness were investigated. Silicon increased the hardness and wear resistance of Al and significantly decreased friction and the oxidation of the implanted surface. These changes were observed to be almost proportional to the implanted dose. The implantation of Pb+ resulted in a linear increase in hardness and a decrease in surface oxidation with dose. Friction decreased and wear resistance increased but the changes were not dose dependent. The implantation of Si+ did not significantly alter the distribution of impurities, such as Fe and Cu within the Al matrix, but Pb+ resulted in a diffusion of Fe to the implanted surface. Formation of precipitates was observed and the improvements in the surface properties studied are considered to result from precipitation hardening, which involves the impediment of dislocation movement by the precipitates during plastic deformation of the implanted Al.


2010 ◽  
Vol 154-155 ◽  
pp. 79-82
Author(s):  
Bo Lin He ◽  
Fang Tu ◽  
Jing Liu

CrZrCu is extensively used in spot welding due to their high electrical, thermal and mechanical performance. But when CrZrCu electrode is used in spot welding of galvanized steel sheet, the abrasion, corrosion and oxidation shorten the electrode life rapidly. The electrode is not able to meet the needs of spot welding of galvanized steel sheet .In the paper, double glow plasma discharge surface titanizing was carried out on CrZrCu alloy. The processes of double glow plasma discharge titanizing, surface alloying layer structure were also analyzed elementary. The wear resistance property of glow discharge plasma titanizing layer was also researched. The experimental results indicated that in the plasma titanizing alloying layer, the diffusion of titanium element toward the interior of the CrZrCu alloy substrate forms the intermetallic compound named Cu4Ti, which is beneficial to the reinforcement of CrZrCu substrate. The experimental results confirmed that double glow plasma discharge titanizing could improve the wear resistance of CrZrCu alloy greatly. Under the external load of 300N and 500N, the wear resistance of double glow plasma discharge titanizing layer is7 times and 8.5 times than that of CrZrCu.


2011 ◽  
Vol 46 (13) ◽  
pp. 1521-1534 ◽  
Author(s):  
H Kaftelen ◽  
ML Öveçoğlu

Elemental aluminum (Al) powders reinforced with 1–10 wt% of ultra-dispersed nanodiamond (UDD) powders were ball-milled in a SpexTM Mixer/Mill between 0 and 120 min followed by consolidation and sintering. X-ray diffraction analyses on the ball-milled powders revealed only α-Al peaks, whereas Al4C3 phase was identified along with α-Al in all sintered composites. Increasing the addition of nanodiamond to Al-matrix resulted in improved hardness of both ball-milled and sintered composites. The wear resistances of the Al-UDD composites were significantly improved with increasing UDD contents. Under similar load and sliding conditions, the wear resistance of Al matrix composite containing 10 wt% nanodiamond enhances about 40 times when compared with unreinforced aluminum.


2013 ◽  
Vol 734-737 ◽  
pp. 2369-2372
Author(s):  
Lei Lei Gao ◽  
Jin Zhong Zhang

A commercial Mg alloy was prepared through equal channel angular extrusion (ECAE) process. The effect of ECAE on mechanical and tribological properties of the alloy was investigated. Experimental results showed that the hardness and strength of the alloy with ECAE were higher than that of the alloy without ECAE and increased with the increase pass number. The friction coefficient and wear resistance of the alloy after ECAE were significantly improved.


Author(s):  
I.N. Kavaliova ◽  
E.A. Kovalev ◽  
A.Ya. Grigoriev

The paper presents data on measurements of friction and adhesion forces of silicon ball and silicon plate covered by DDPO4 (dodecylphosphoric acid ester), ODPO4 (octadecylphosphoric acid ester), SEBS (poly[styrene-b-(ethylene-co-butylene)-b-styrene]) and OTS (octadecyltrichlorsilane) and others. Tests were performed with reciprocating microtribometer and contact adhesion meter. The experimental results have shown, that coefficient of friction, between a silicon ball and silicon substrates modified by the monomolecular films, are varied in the range 0.05…0.25, with wear-resistance from 20 to 2000 cycles. An ambiguous correlation was found between friction and contact adhesion forces of investigated surfaces.


2019 ◽  
Vol 956 ◽  
pp. 237-243
Author(s):  
Yi Qiang He ◽  
Chang Xu Ren ◽  
Hu Lin Xu

Spray deposited SiCP/Al-Fe-V-Si composite is characterized with pores and oxide films between deposited particles, therefore further densification is needed. Densification of the composite preforms in large size has becomes the research emphasis and challenge. Current research of the composite is focused on densification technologies used to eliminate metallurgical defects. Key parameters of wedge pressing, density and stress distribution, flow behaviour, densification mechanism and regularity are investigated by combining experiment and finite element modelling. Pass reduction of 10%~15% and space of about 10mm between one end of the plate blank and the steel mould is beneficial to wedge pressing because of the effective deformation. Density and stress of the external layer are higher than that of the inter layer, density and stress distribution become uniform with overall reduction. Materials in preformed area flows along thickness direction as thickness of the plate decreases, while materials in main deformation area flows along length direction with increasing length of the plate. Wedge pressing of the spray deposited Al matrix composite plate follows porous metal plastic deformation mechanism under the condition of plane strain. Practical relative density of the plate is higher than the calculated value in the initial stage of pressing, while the practical relative density becomes lower than the calculated value as true strain exceeds 0.55, which can be attributed to the pores resulted from aggregation and breaking of SiC particles.


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