In specialised solidification processing techniques such as High Pressure Die Casting, Twin-Roll Casting and others, an additional external deformation load is applied to achieve the required shape, leading to the formation of microstructural features such as shear bands. The mechanism for forming these features is believed to be dependent on dynamically evolving strain fields, which are dependent on the local solid fraction, applied strain rates and casting geometry. To investigate this, a semisolid ($\sim$ 50 % solid fraction) Al-10 wt.% Cu alloy is isothermally injected into a bespoke die using a custom-designed thermo-mechanical rig. The semisolid deformation, formation of Cu-rich dilatant bands and subsequent pore nucleation and growth are captured using fast synchrotron X-ray radiography. The local normal and shear strains acting on the mush are quantified using digital image correlation to identify the dilatant shear bands and the dominant local strain component. Correlating the radiographs with strain maps reveals that gas pores within the dilated interstices grow, while those in compressed regions are squeezed out. A linear correlation between accumulated volumetric strain and porosity volume fraction demonstrates that higher dilations give rise to a local increase in both gas and shrinkage porosity.

在高压压铸、双辊铸造等专门的凝固加工技术中，会施加额外的外部变形载荷以达到所需的形状，从而形成剪切带等微观结构特征。形成这些特征的机制被认为取决于动态演化的应变场，这取决于局部固体分数、施加的应变率和铸件几何形状。为了研究这一点，一个半固体（$～$50 % 固体分数) Al-10 wt.% Cu 合金使用定制设计的热机械设备等温注入到定制模具中。半固态变形、富铜膨胀带的形成以及随后的孔隙成核和生长是使用​​快速同步加速器 X 射线照相捕获的。作用在糊状物上的局部法向和剪切应变使用数字图像相关性进行量化，以识别剪胀剪切带和主要的局部应变分量。将射线照片与应变图相关联表明，膨胀间隙内的气孔增长，而压缩区域中的气孔被挤出。累积体积应变和孔隙体积分数之间的线性相关性表明，更高的膨胀会导致气体和收缩孔隙率的局部增加。