Modeling of dynamic recrystallization volume fraction evolution for AlCu4SiMg alloy and its application in FEM

To improve the understanding of coupling effect between dynamic recrystallization(DRX)behaviors and flow behaviors of as-cast AlCu4 SiMg, a finite element(FE) simulation equipped with the models of DRX evolution was implemented. A series of isothermal compression tests were performed primarily on a Gleeble-3500 thermo-mechanical simulator in a temperature range of 648-748 K and a strain rate range of 0.01-10 s-1.According to the measured true stress-strain data,the strain hardening rate curves(dσ/dε versus σ) were plotted to identify the critical strains for DRX initiation(εc). By further derivation of the related material constants, the DRX volume fraction equation and the strain for 50% DRX(ε0.5) equation were solved. Accordingly, the aforementioned DRX equations were implanted into the FE model to conduct a series of simulations for the isothermal compression tests. The results show that during the evolution of DRX volume fraction at a fixed strain rate, the strain required for the same amount of DRX volume fraction increases with decreasing temperature. In contrast, at a fixed temperature, it increases with increasing strain rate. Ultimately, the DRX kinetics model of AlCu4 SiMg alloy and the consequence of the FE analysis were validated by microstructure observations.

Artificial intelligence model of complicated flow behaviors for Ti-13Nb-13Zr alloy and relevant applications

The comprehensive nonlinear flow behaviors of a ductile alloy play a significant role in the numerical analysis of its forming process. The accurate characterization of as-forged Ti-13 Nb-13 Zr alloy was conducted by an improved intelligent algorithm, GA-SVR, the combination of genetic algorithm(GA) and support vector regression(SVR). The GA-SVR model learns from a training dataset and then is verified by a test dataset. As for the generalization ability of the solved GA-SVR model, no matter in β phase temperature range or(α+β) phase temperature range, the correlation coefficient R-values are always larger than 0.9999, and the AARE-values are always lower than 0.18%. The solved GA-SVR model accurately tracks the highly-nonlinear flow behaviors of Ti-13 Nb-13 Zr alloy. The stress-strain data expanded by this model are input into finite element solver, and the computation accuracy is improved.

Primary malignant lymphoma of the glans penis： a rare ：ase report and review of the literature

Dear Editor, We present here a rare case of primary malignant lymphoma of the glans penis that was detected in a 72-year-old man. Additionally, we have reviewed the literature for reports of primary malignant lym phoma of the penis. This is most likely the forty-ninth case of primary malignant lymphoma of the penis reported in the medical literature. Lymphomas typically originate from the lymph nodes and lymph tissues; however, the tonsils, spleen and bone marrow are also vulner- able sites. Due to the presence of lymph nodes and lymph tissue throughout the human body, primary malignant lymphomas of glans penis occur rarely. The diagnosis of this rare lymphoma may be dif- ficult and delayed without specific symptoms, and treatment modali- ties are controversial because of the limited number of patients. A 72-year-old male patient was referred to our hospital due to a mass on the left side of the glans penis in May 2007. A physical exa- mination identified two masses, one on the left tip and one on the right tip of his penis. The left lump measured approximately 8 mm in diameter, was hard in nature, and was cystic, reddish in colour and covered the surface of the glans penis with ill-defined margins. There was no visible ulceration and no tenderness on palpation. The cystic mass on the right side measured 15 mm; the lesion was firm in nature, did not protrude from the surface and had no palpable tenderness. The liver and spleen were not palpable, and no other sites oflymphadeno- pathy were observed; B symptoms were absent. Anti-inflammatory treatment was administered at another hospital, but it was unsuccess- ful. On 17 May 2007, the two masses were resected with penile pre- servation. The pathological examination showed the presence of a malignant lymphoma originating from B cells （diffuse large B）, as shown in Figure 1. The patient was diagnosed with diffuse large B-cell lymphoma of the glans penis, stage IE, according to the Ann Arbor classification. No obvious distal metastasis was found by chest X-ray or abdominal ultrasonography before the surgery.