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This paper aims to research the high-temperature oxidation behavior of TiC/Mo composite. Adding 5 wt.% TiC, Mo-based composite was prepared by Spark Plasma Sintering. The composite was oxidized at different temperatures (400°C, 600°C, 800°C, 1000°C and 1200°C) and times (5 min, 10 min, 20 min, 30 min and 60 min). When oxidation was at 400-1000°C for 20 minutes, the degree of oxidation intensifies with the increase of temperature, and TiO2 was observed at 1000°C. While the temperature was 1200°C, the oxidation rate gradually decreased with the increase of time. The result shows that the formation of TiO2 can inhibit the oxidation process.

In this study, the two types of high-strength low-alloy steels were melted and cast in a vacuum induction furnace. Phase transition temperature of HSLA steel was calculated by JMatPro software. The calculation results show that the two different types of HSLA steels which have equal phase proportions of ferrite and austenite at a temperature of approximately 820 and 800 °C in HSLA-I and HSLA-II, respectively. In addition, the effect of chemical composition on the microstructure and mechanical properties of steels were studied. The results indicate that the ultimate tensile stress value of HSLA-II samples was greater than the HSLA-I samples by about 35%, and the yield stress and breaking strength value of HSLA-II were higher than HSLA-I as well.

Background Endometriosis of the uterine body can be manifested as diffuse solid lesions or cystic lesions. The former is common, while the latter is rare, especially for cystic adenomyosis larger than 5 cm. Case presentation A 30-year-old woman was admitted for severe and worsening dysmenorrhea. Ultrasound examination revealed a rare well-circumscribed cystic lesion about 5.5 × 4 × 5.0 cm. CA-125 level was slightly elevated. She accepted laparoscopic surgery and the adenomyotic tissues were excised. The histopathology of the specimen demonstrated the endometrial glands in the walls of cysts and an area of extensive hemorrhage can be seen in the inner wall of cyst. The patient made a good recovery after surgery and her symptoms complete resoluted. Conclusions This is a rare case of a cystic adenomyotic lesion that was treated by laparoscopic surgery.

Background: Laparoscopic sacrocolpopexy (LSC), which is an important procedure for vault prolapse, has the advantages of high cure rate, low recurrence rate and little impact on sexual life. Few nerve entrapment complications have been reported in the literature.Case presentation: A 48-year-old woman developed persistent lumbosacral and right-sided gluteal pain after the LSC. During diagnostic laparoscopy, we found that the fixation site deviated by approximately 1.5 cm from the middle of the sacral promontory, the anterior surface of the first sacral vertebra. Hence we removed most of the mesh carefully. S1 nerve “entrapment” caused by this deviation, accompanied by the tissue fibrosis and scar tissue formation, may have been the main cause of pain. The patient’s symptoms resolved after surgical intervention. Conclusions: Our case emphasizes that sacral nerve entrapment is a potential complication of retroperitonealized synthetic mesh placement during sacrocolpopexy. We hope that this report can serve as a reference for dealing with similar situations. For skilled laparoscopists, laparoscopic mesh removal is safe and feasible, but attention should be paid to avoid damage to vessels, ureters and other important organs.

In the scope of refractory material processed by spark plasma sintering development for structural applications in the core of future combustion chamber, Mo-TiC alloys and Mo-TiC-Cr alloys were sintered at 1700°C with a pressure of 30 MPa. Powders of Mo, TiC and Cr were prepared by planetary ball mill in an argon atmosphere. In this dissertation, the structure, element and phase composition of alloys were investigated. The Mo-TiC alloys showed obvious intergranular brittle fracture. The fracture mode of Mo-TiC-Cr alloys, however, was changed to mixed intergranular and transgranular fracture. The obtained results demonstrated that, compared with the peaks of Mo and Mo2C from Mo-TiC, the peaks of Mo and Mo2C from Mo-TiC-Cr were deflected to the right, due to the addition of chromium forming a solid solution. The results of isothermal oxidation tests at 1200°C in air revealed that the chromium compound on the surface of the oxide layer increases and the pores decreases with the increase of oxidation time for Mo-TiC-Cr alloys. The pores of surface of the Mo-TiC alloys were less and smaller than the Mo-TiC-Cr.

Effects of alloying elements (i.e., variable content of Mo and C) on the microstructure and compression properties of four types of experimental material based on TiAl-based alloy containing 8 at.% Nb were investigated. The specimens were prepared by vacuum noncollapsable melting technology and followed by a homogenization treatment with air cooling. The compression properties at room and at elevated temperature were evaluated in laboratory air. The results demonstrate that the inter-lamellar space of the alloy decreased with the addition of the Cr and Mo alloying elements. Cr acts a better role in grain refinement, while Mo enhances the content of γ phase in the alloys. The addition of Cr/Mo elements improves the elastic modulus of the material, but reduces the breaking strength due to the absence of the dislocation region found in non-Cr / Mo alloys that resist cracking. The concentrated distribution of γ phase at grain boundaries hinders recrystallization and the tendency of grain orientation.

Three novel multi-microalloying TiAl-based alloys containing high Nb were designed and fabricated. Thermogravimetric method was applied to investigate the influence of Cr on the oxidation behavior of high Nb-TiAl alloy at 1,073 K for 200 h in laboratory air. The 2at.% and 4at.% Cr were added into the alloy, (respectively named 2Cr and 4Cr compared to the Cr-free ternary alloy, 0Cr alloy). The alloys’ microstructure and composition as well as the composition distribution of the oxidation scale were analyzed by means of Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-Ray Diffractometry (XRD). The results show that the addition of Cr decreases the grain size of the Nb-TiAl alloy and leads to a transformation from a fully lamellar structure to a nearly fully lamellar structure. When oxidized at 1,073 K for 200 h, the oxidized mass gain of the alloy increases with an increase in Cr addition amount in the first 100 h and decreases in the last 100 h. With the increase of Cr content, the oxidation surface turns compact but uneven in morphology, which may affect the oxidation resistance of the alloy by increasing the peeling off risk of the oxidation layer at friction conditions.

Ti-44Al-9Nb-1Cr-0.2W-0.2Y alloys were directionally solidified (DS) at different growth rates varying from 10 to 20 &mu, m/s using a modified liquid metal cooling (LMC) method. The results show that an increase in the growth rate leads to both a decrease in the size of the columnar grains in the directional solidification stable growth zone and a deterioration of the preferred orientation of the &alpha, 2(Ti3Al)/&gamma, (TiAl) lamellar structure in the columnar grains. The growth direction of the primary dendrite in the quenching zone gradually deflected along the axial direction as the growth rate increased. At the same time, the morphology changed from dendrite to a cystiform dendritic structure, with considerable B2 phase segregation in the dendritic core. Correspondingly, the tensile properties of the alloy decreased at 800 &deg, C with a gradual increase in the cleavage fracture area. These findings show that the low growth rate is beneficial for the preferred orientation and the mechanical properties of the alloy. The content of the B2 phase and the change in the lamellar orientation are the main limiting factors for the tensile properties of the materials at high temperatures.

Based on heavy chassis dynamometer, an experimental study was conducted in diesel buses compliant with China Ⅲ,Ⅳ,Ⅴ emissions standards respectively, fueled with three different blends of petroleum diesel/biodiesel (0%,5%and 10%