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The dissimilar butt joining of aluminum alloy and copper was successfully realized by cold metal transfer (CMT) welding–brazing with the help of preheating on copper. Preheating could balance the effect of the high thermal conductivity of copper on weld formation, and eliminate welding defects such as porosity, unfused zone, and cracks at the interface. Three layers of intermetallic compounds were observed at the brazing interface, namely, Al4Cu9, Al2Cu3, and Al2Cu. When the heat input was reduced to 648 J/mm, the total thickness of the interfacial IMC layers was suppressed to 4.83 μm, and the mechanical property of the joint was up to 91.35 MPa. The corrosion resistance of the Al/Cu welded joint was worse than that of the base metals, and corrosion occurred at the interfacial IMCs and the grain boundaries of the weld microstructure. [ABSTRACT FROM AUTHOR]

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Background: Previous data were not conclusive on the safety of gestation in patients whose abdominal flaps were earlier harvested. We performed a meta-analysis to evaluate the abdominal wall complications and birth mode of pregnancy in post-TRAM or post-DIEP harvested individuals. Methods: A literature search was performed using the PubMed, Embase, Scopus, and Google scholar database. Heterogeneity was statistically analyzed, and random effect models were applied. Publication bias was assessed by funnel plot. Results: We included 25 papers that captured 56 patients giving birth to 69 healthy babies after elevation of abdominally based flaps, with a pooled abdominal complication rate of 0.00–0.09. The complication incidence in TRAM group was 0.01 (95% CI = [0.00–0.14%]) while 0.00 in the DIEP group (95% CI = [0.00–0.26%]). Discrepancies in incidence following unilaterally or bilaterally based TRAM flaps, following free or pedicled TRAM flaps, following primary sutured or mesh strengthened fascia, following MS free TRAM or conventional free TRAM could not be calculated as statistically significant. TRAM group and DIEP group patients had identical birth modes. Conclusions: The present meta-analysis did not detect evidence that abdominal walls with the prior harvest of abdominal flaps could affect the process of pregnancy or contraindicate vaginal delivery. No abdominal hernia or bulge occurred with post-DIEP pregnancies. However, such conclusions need to be substantiated by larger sample studies. Level of Evidence III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

The equiatomic CoCrFeMnNi high entropy alloy, which crystallizes in the face-centered cubic (FCC) crystal structure, was prepared by the spark plasma sintering technique. Dynamic compressive tests of the CoCrFeMnNi high entropy alloy were deformed at varying strain rates ranging from 1 × 10 to 3 × 10 s using a split-Hopkinson pressure bar (SHPB) system. The dynamic yield strength of the CoCrFeMnNi high entropy alloy increases with increasing strain rate. The Zerilli-Armstrong (Z-A) plastic model was applied to model the dynamic flow behavior of the CoCrFeMnNi high entropy alloy, and the constitutive relationship was obtained. Serration behavior during plastic deformation was observed in the stress-strain curves. The mechanism for serration behavior of the alloy deformed at high strain rate is proposed. [ABSTRACT FROM AUTHOR]

Ion implantation is widely used in semiconductor manufacturing to modify electrical properties of the near-surface region of silicon wafers. The efficiency of ion implantation process deeply relies on wafer transfer procedure. Increasing wafer transfer speed is one of the most efficient ways to accelerate the ion implantation process for higher productivity of silicon chips. This study focuses on developing an efficient scheme for wafer transfer procedure to acquire higher transfer speed and reduce cycle time during ion implantation process. The scheme we proposed improves the layout of the vacuum chamber in currently used ion implanter by introducing an additional wafer transfer robot inside while placing the alignment station outside, planning optimal motion sequence of three wafer transfer robots in order to make all of them keep working without spending a long time waiting for other robots. Experimental platform has been established and the results show that wafer transfer speed based on the proposed scheme is over three times faster than the commonly used apparatus. [ABSTRACT FROM AUTHOR]