Advanced Materials Research Vol. 893

Abstract: Over the past few years, several extensions of the traditional control charts have been proposed to adapt to the fuzziness inevitably existing in practical manufacturing processes. This paper proposed a fuzzy u chart to monitor the nonconformity of industrial products. A thorough evaluation of manufacturing conditions was also developed with certain categorization rules which can classify the process into four consequences, including in-control, rather in-control, rather out-of-control and out-of-control. With an empirical study of monitoring the weld discontinuities, our proposed approach can efficiently provide more sufficient and justified classification results in contrast with the traditional online processes monitoring methods.

Abstract: The purpose of this study is to enhance the strength of steel by increasing the percentage of martensite microstructure with a high pressure water jet quenching. JIS SS400 carbon steel was chosen as a test sample. The cooling rate of surface and center reached approximately 180oC/sec and 65oC/sec, respectively. After this quenching process, the metallographic analysis showed that the steel turned into martensite structure. Furthermore, the tensile strength of sample increased from 363MPa to 543MPa; the yielding strength increased from 284MPa to 420Mpa. In general, the overall enhancement of mechanical strength was about 140%.

Abstract: This article is for the integrity of the cutting surface, explaining the reason for the cutting residual stress generated from the mechanism, proposed several typical methods to reduce the residual stress. According to some experimental researches on cutting parameters which have been done by previous scholars, this article gives some analysis of the effects of cutting parameters of residual stress. And preliminary summary of the influence of residual stress on cutting parameters, it also provides a way for further discussion of cutting parameters and material effect on the machined surface residual stress distribution law.

Abstract: This paper studies the influence of the intermediate annealing on deformation ability of the cold rolled ring. The results show that: intermediate annealing can improve the ability of plastic deformation of the cold rolled ring, ring rupture occurred after 62.5% thickness reduction, on the other side the ring suffering intermediate annealing still be intact by rolling to upon 64.8% thickness reduction. The mechanism of the intermediate annealing improving deformation ability of cold rolled ring is explored by using optical microscopy, scanning electron microscopy, micro hardness tester and other materials characterization methods. It is found that after intermediate annealing, the amount of carbide particles significantly reduce and the hardness decrease. Meanwhile, dissolution of partial carbides occur during the cold ring rolling process, and with the increasing of the cold rolling deformation, the quantity of the dissolution of cementite in pearlite will increase, which resulting in the improvement of the deformability of the cold rolled ring.

Abstract: The effect of different elements of the auxiliary material on the grinding performance was studied in this paper. Through the grinding experiment, the grinding performance of the abrasive tool can be obtained. It shows that the grinding rate decreased until its content reached to16% following with increasing the NaHCO₃ content. And the abrasive removal rate reduced, while the grinding efficiency was lower than the abrasive tool without adding NaHCO₃. When ZnO content was reached 3%, the grinding rate increased by 43.48% and the grinding efficiency was also improved; while continue to increase its content, the abrasive`s self-sharpening were reduced, which resulting the grinding rate declined. As the NBR (nitrile rubber) content increased, the grinding rate improved and while its content was 20%, the grinding rate increased by 45.93% and the abrasive removal rate reached to the lowest, but the grinding efficiency reduced more. While continue to add NBR, the grinding rate will decrease.

Abstract: MQL system is introduced in this paper to verify the influences on the tool wear and cutting force that brought by MQL (minimal quantity lubrication) for high-temperature alloy. The system utilized various pressures that are caused by the compressed air flowing through the decrescent areas to absorb the liquid from the reservoir tank, and then the liquid was transported to the nozzle which could spray the liquid on the workpiece for cooling and lubrication. The results shown that MQL had an obvious advantage over dry cutting and traditional cooling methods; it could effectively reduce cutting forces and improve the tool life expectancy as well as processing quality and efficiency. The proposed method also had some other positive characteristics, such as the less dosage of cooling fluid and the environmental-friendly. It also can be applied to the processing of difficult-to-cut materials with a wide range of prospects.

Abstract: In this study, MCM-41 was synthesized by hydrothermal method, using non-toxic sodium metasilicate nonahydrate as the silicon source, cetyl trimethyl ammonium bromide (CTAB) as template, and sulfuric acid as the pH value adjustment agent. The effects of ratio of template agent to silicon source, pH value, crystallization temperature and crystallization time on the yield and crystallization of MCM-41 were investigated. MCM-41 was then characterized by XRD, FTIR, SEM, TEM and N₂ adsorption-desorption testing techniques. Rhodamine B adsorption studies were carried out to study the effects of pH value and reaction time on the adsorption properties of MCM-41. The resulting MCM-41 had smooth surface with a pore size of 3-4nm and an average diameter particle of about 5μm. It had high specific surface area up to 784m²/g, thus adsorption rate of MCM-41 for rhodamine B obtained 93% when pH=3, t=15min. The reaction fitting curve of the Lagergren first order reaction model was lg (q_e-q_t) =-0.00586-0.803t, R² = 0.97582.

Abstract: The process of grinding-drill is simulated by using of deform-3D. it is analyzed that deferent face structure of grinding-driller influences grinding-drill process. The reasonable taper vertex angle and amount of eccentric of the grinding-driller are gained by means of the smallest axial force & torque & lower cutting temperature. So that the reasonable face structure of grinding-driller will be gained.

Abstract: Interference-fit joining is one of the important jointing methods to permanently fasten two thin-walled sheet metal parts. In joining process the interference amount is an important factor, which affects ultimate strength and fatigue life of the mechanical structure. In this article, analytical solution for interference value is studied, and the elastic and plastic deformation area near the hole is discussed. The calculation formula for the hole walls displacement and the boundary between elastic and plastic deformation is obtained.

Abstract: A 3D finite element model was established using the software ANSYS to simulate the inclusions trajectories and residence time in refining TiAl alloys during PAM process. The results show that tungsten, molybdenum and niobium inclusions can be removed by the mushy region entrapment, and all of these particles which diameter is larger than 40μm are captured in the pool bottom. The residence time of inclusion depends on the particle density and size. The bigger the inclusion density or the lager the inclusion diameter, the shorter the residence will be. Moreover, the inclusions trajectories and residence time are influenced by the hydrodynamics of the melt. The buoyancy force and the drag force provided by melt drive the inclusion particles moving in the pool.