CAJ | 학술논문

对过共晶 Al-20%Si 合金进行变质和合金化处理,并在不同环境温度下进行摩擦磨损测试.结果表明,经过Cu-P中间合金变质后的初晶Si相和共晶Si相明显细化和钝化,再添加1.5%Zr (质量分数)后初晶Si相的粒径更小,为20~40μm,且趋于球形.共晶Si相呈纤维状或短棒状,长度明显变短(≤50μm).以上3种合金随环境温度的升高都出现了从轻微磨损到严重磨损的转变,且转变载荷随环境温度的升高而减小.室温下3种合金的磨损曲线差异不大,但在较高的环境温度下,经变质和合金化处理后,发生磨损转变的载荷明显减小,细化的初晶和共晶Si相提高了合金的性能,特别是高温耐磨性能.这归因于细化的Si相避免了应力集中和磨损过程中的直接破碎化,在高温磨损阶段磨损表面易形成机械混合层,阻碍合金与对磨副的直接接触,降低磨损率.
대과공정 Al-20%Si 합금진행변질화합금화처리,병재불동배경온도하진행마찰마손측시.결과표명,경과Cu-P중간합금변질후적초정Si상화공정Si상명현세화화둔화,재첨가1.5%Zr (질량분수)후초정Si상적립경경소,위20~40μm,차추우구형.공정Si상정섬유상혹단봉상,장도명현변단(≤50μm).이상3충합금수배경온도적승고도출현료종경미마손도엄중마손적전변,차전변재하수배경온도적승고이감소.실온하3충합금적마손곡선차이불대,단재교고적배경온도하,경변질화합금화처리후,발생마손전변적재하명현감소,세화적초정화공정Si상제고료합금적성능,특별시고온내마성능.저귀인우세화적Si상피면료응력집중화마손과정중적직접파쇄화,재고온마손계단마손표면역형성궤계혼합층,조애합금여대마부적직접접촉,강저마손솔.
The hypereutectic Al-20%Si alloy was treated by modification and alloying. The wear tests were conducted under various ambient temperatures. The results show that after modification of Cu-P master alloy, the primary and eutectic Si phases are significantly refined and passivated. After adding 1.5%Zr (mass fraction) again, the shape of primary Si becomes spherical and the particle size becomes smaller, being 20?40 μm? a fibrous or short rod shape eutectic Si phase forms in the modified alloy, the length is less than 50 μm. The mild-to-severe wear transition occurs with increasing the load, and the critical loads reduce with rising the ambient temperature for the three aluminum alloys. The changing trend of wear curves of three alloys is similar at room temperature, but the critical loads of wear transition reduce after the modification and alloying at high ambient temperatures. The refinement of primary and eutectic Si phase obviously increases the alloy performance, especially the wear resistance at elevated temperature. This is attributed to the refined Si phase avoiding the stress concentration and direct fragmentation during wear process. And mechanical mixed layer is very easy to form in the elevated temperature wear process, which hinders the direct contact between the alloy and the counterface and decreases the wear rate.