Even though Mg alloys containing Mn and rare earth elements lead to higher ductility and lower yield asymmetry due to the weak texture after extrusion, plastic instability, commonly known as the Portevin–Le Chatelier (PLC) effect, causes unexpected fragility in the service environment. In the present study, the PLC phenomenon and texture development during the deformation of Mg-Mn and Mg-Mn-Nd extruded alloys were investigated under various temperatures and strain rates. The addition of Nd causes not only texture weakening but also severe PLC phenomenon. The PLC phenomenon was significantly affected by the temperatures and the strain rates, which causes a difference in mechanical properties and development of texture. In the conditions of high temperature and low strain rate, the strength increased while the elongation decreased significantly, and obvious PLC phenomenon with severe serration and negative strain rate sensitivity. The initial texture was maintained even after deformation only under severe PLC conditions, and this is due to the restriction of basal slip and suppression of lattice rotation in PLC conditions. The series of results indicate that the PLC phenomenon causes a reduction of formability even at high temperature.

尽管含有 Mn 和稀土元素的 Mg 合金由于挤压后织构较弱而导致较高的延展性和较低的屈服不对称性，但塑性不稳定性，通常称为 Portevin-Le Chatelier (PLC) 效应，会在使用环境中造成意想不到的脆弱性。在本研究中，研究了不同温度和应变速率下 Mg-Mn 和 Mg-Mn-Nd 挤压合金变形过程中的 PLC 现象和织构发展。Nd的添加不仅会导致织构弱化，还会导致严重的PLC现象。PLC现象受到温度和应变率的显着影响，导致机械性能和织构发展的差异。在高温、低应变率条件下，强度增加而伸长率明显下降，和明显的PLC现象，锯齿严重，应变率负敏感性。即使在严格的 PLC 条件下变形后，初始织构仍保持不变，这是由于 PLC 条件下基底滑移的限制和晶格旋转的抑制。这一系列结果表明，即使在高温下，PLC 现象也会导致成型性降低。