CAJ | 학술논문

利用TEM和HRTEM研究Mg-8Zn-4Al-1Ca合金的时效微观组织。结果表明：Mg-8Zn-4Al-1Ca合金较Mg-8Zn-4A1合金时效硬度显著增高。Mg-8Zn-4Al-1Ca合金在160°C时效16 h，有大量的盘状Ca2Mg6Zn3相沉淀弥散析出，此外，合金的微观组织中还存在晶格畸变、蜂窝状的莫尔条纹、刃型位错及位错环；经48 h时效后合金中沉淀相为粗大的盘状沉淀相和细小、弥散的粒状沉淀相；经227 h 时时效后后，其组织中存在大量MgZn2相和Ca2Mg6Zn3相。因此，在Mg-8Zn-4Al-1Ca时效160°C的合金中添加Ca元素能有效提高合金的时效硬度及促进MgZn2强化相的生成。
이용TEM화HRTEM연구Mg-8Zn-4Al-1Ca합금적시효미관조직。결과표명：Mg-8Zn-4Al-1Ca합금교Mg-8Zn-4A1합금시효경도현저증고。Mg-8Zn-4Al-1Ca합금재160°C시효16 h，유대량적반상Ca2Mg6Zn3상침정미산석출，차외，합금적미관조직중환존재정격기변、봉와상적막이조문、인형위착급위착배；경48 h시효후합금중침정상위조대적반상침정상화세소、미산적립상침정상；경227 h 시시효후후，기조직중존재대량MgZn2상화Ca2Mg6Zn3상。인차，재Mg-8Zn-4Al-1Ca시효160°C적합금중첨가Ca원소능유효제고합금적시효경도급촉진MgZn2강화상적생성。
The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A dense dispersion of disc-like Ca2Mg6Zn3 precipitates are formed in Mg-8Zn-4Al-1Ca alloy aged at 160 °C for 16 h. In addition, the lattice distortions, honeycomb-looking Moiré fringes, edge dislocations and dislocation loop also exist in the microstructure. The precipitates of alloy aged at 160 °C for 48 h are coarse disc-like and fine dispersed grainy. When the alloy is subjected to aging at 160 °C for 227 h, the microstructure consists of numerous MgZn2 precipitates and Ca2Mg6Zn3 precipitates. All the analyses show that Ca is a particularly effective trace addition in improving the age-hardening and postponing the formation of MgZn2 precipitates in Mg-8Zn-4Al alloy aged at 160 °C.