摩托车发动机用Ti-Al-Fe-Mo气门的制备及性能表征

Preparation and properties characterization of Ti-Al-Fe-Mo valves for motorcycle engines

摘要:

以Ti粉和Al、Fe、Mo等元素粉末为原料,采用粉末冶金工艺制备了Ti-Al-Fe-Mo合金,并最终制成摩托车发动机用钛气门,研究了钛合金制备过程中的组织和性能演变规律,考察了钛气门的装机试验使用效果。结果表明,采用粉末冶金工艺制备的Ti-Al-Fe-Mo合金具有优良的综合性能,其抗拉强度为1232 MPa,屈服强度为1186 MPa,延伸率为6.5 %,硬度为49 HRC。在钛合金表面涂覆TiN硬质耐磨涂层后,制成的钛气门可满足摩托车发动机的装机测试要求。与使用钢制气门相比,使用钛气门可以使发动机的功率和扭矩提高约12%,油耗降低1%,并显著降低噪音。

Abstract:

Ti-Al-Fe-Mo alloy was prepared by powder metallurgy method with titanium, aluminum, molybdenum and iron powders used as raw materials, and the alloy was used to fabricate valves for motorcycle engines. The microstructure as well as performance evolution of the alloy during the preparing process was investigated. The performances of motorcycle engines assembled with Ti valves were also tested. The results show that Ti-Al-Fe-Mo alloy prepared by powder metallurgy has excellent comprehensive performances with ultimate tensile strength 1232 MPa, yield strength 1186 MPa, elongation 6.5% and hardness 49 HRC. The fabricated valves after coating TiN can meet the requirement of on board tests of the motorcycle engine. Compared with assembling steel valves, power and torque of the motorcycle engines assembled with Ti valves are improved by about 12%, fuel consumption rate is reduced by 1% and the noise is also significantly lowered.