By studying microstructural effects on the mechanical and tribological behaviors of aluminum bronzes, a novel high-strength wear-resisting aluminum bronze (KK) has been developed by optimizing microstructures, modifying, adding special elements and controlling the casting process. The mechanical properties, friction and wear behavior of this alloy have been tested and compared with two other commercial aluminum bronzes of the same class. Experimental results show that the properties of the novel KK bronze are much superior to those of the other bronzes.

Microstructural effects on mechanical and tribological behaviours have been studied for a series of aluminium bronzes with different microstructures. ASTM 1045 and 52100 steels were used as the counterparts in the friction and wear tests. Experimental data show that the coefficients of friction, wear rate and mechanical properties strongly depend on the volume fraction of a-phase present in the alloy and, to a lesser extent, on the average a-grain size. The minimum coefficients of friction and the wear rate correspond to a yield strength of 370 Nmm-2 and a bulk hardness of liB 168. Except for extreme low average a-grain size (corresponding to low volume fraction), both the coefficients of friction and the wear rate show linear relations with the reciprocal of the yield strength of the alloy, but not to the reciprocal of the hardness as expected. Based on these results, a design principle for high strength wear-resistant aluminium bronze has been developed.

The remarkable tribological behavior of a novel high-strength, wear-resisting zinc-based alloy, named ZMJ, which is aimed to replace bronze as an engineering material, has been studied. A desirable wear-resisting microstructure was achieved through a specially designed composition and casting procedure. The micro-constituents and microstructures were studied, their relationships with the mechanical, anti-friction and wear-resisting properties having been analyzed both qualitatively and quantitatively. It was found that the microstructure of ZMJ plays a dominant role in providing its superior wear-resisting properties. The composition of ZMJ consists of Zn, Al, Cu, Mg, Mn, Ti, B and rare earth elements. The functions of each of these alloying elements have been explained in detail. This novel alloy's strengthening mechanisms and wear mechanisms have been studied and compared with those of phosphor-tin-bronze ZCuSn10P1 (GB1176-87) and the popular ZA-27 (ASTM B669-82) zinc-based alloy. ZMJ has been proven to be an excellent engineering material by comparing its mechanical properties and friction and wear properties with those of ZCuSnlOP1 and ZA-27. Industrial applications in gears, worm-gears, bearing and bushes etc. have shown that ZMJ brings significant benefits in energy saving and enhances the quality and life expectancy of these machinary parts.

Friction and wear characteristics of a Zn-27% Al-2% Cu alloy, modified with Ti and misch metal, with different Mn contents, coupled with steel have been studied. A pin-on-disk tribometer was used to measure the friction coefficient of alloy samples under different loads, speeds and lubricating conditions while the wear volume and temperature rise of the lubricant were measured by a cylinder-on-ring wear tester. Friction and wear characteristics of these Mn-containing alloys were compared with those of ZA-27. Effects of Mn content on the tribological behaviors and microstructures were studied and the relationships between the tribological characteristics and the microstructures of the alloy were also analyzed. Experimental results indicate that the addition of Mn can significantly improve the tribological behaviors of the Zn-27% Al-2% Cu alloy. Finally, an optimum Mn content for the best overall mechanical properties and tribological behaviors was obtained.

Effects of different sintering temperature and sintering time on the relative density of the sintered compacts were studied to obtain the optimal sintering parameters for the fabrication of NbC patti culate reinforced iron-base compos ire. With optimal sintering temperature of 1280℃ and sintering time of 80min, wear-resisting, high density NbC particulate reinforced iron-base composites can be obtained using warm compaction powder metallurgy. The microstructure, relative density, mechanical properties and tribologieal behaviors of the sintered composites were studied. The results indicate that the mechanical properties of the sintered compacts were closely related to the sintered density. The iron base composite materials with different combinations of mechanical properties and tribological behaviors were developed for different applications. One of the developed composite, which contains 10% NbC, possesses a high strength of 815MPa with a remarkable friction and wear behaviors. The other developed composite, which contains 15% NbC, possesses a lesser strength of 515 MPa but with exeeUent friction and wear behaviors.