Room-temperature mechanical properties of Cu50Zr40Ti10–xNix (0≤x≤4, mole fraction, %) bulk metallic glasses (BMG) with aspect ratios in the range of 1:1–2.5:1 and loading rates in the range of 1×10−5–1×10−2 s−1 were systematically investigated by room-temperature uniaxial compression test. In the condition of an aspect ratio of 1:1, the superplasticity can be clearly observed for Cu50Zr40Ti10 BMG when the loading rate is 1×10−4 s−1, while for Cu50Zr40Ti10–xNix (x=1–3, mole fraction, %) BMGs when the loading rate is 1×10−2 s−1. The plastic strain (ɛp), yielding strength (σy) and fracture strength (σf) of the studied Cu-based BMGs significantly depend on the aspect ratio and the loading rate. In addition, the σy of the studied Cu-based BMGs with an aspect ratio of 1:1 is close to the σf of those with the other aspect ratios when the loading rate is 1×10−2 s−1. The mechanism for the mechanical response to the loading rate and the aspect ratio was also discussed.

A group of plastic Zr-Al-Ni-Cu bulk metallic glasses (BMGs) with low Zr content was developed and their thermal and mechanical properties were investigated. The results show that these Zr-based BMGs have a single crystallization event for all heating rates in the studied temperature region. The glass transition temperature Tg decreases with increasing Zr content for all heating rates. There are two melting procedures for the BMGs whose Zr content is less than 52 at %, while three melting procedures for the other Zr-based BMGs. The second melting procedure is split into two melting procedures for Zr52.5Al12.2Ni12.6Cu22.7 and Zr53Al11.6Ni11.7Cu23.7 BMGs, while the first melting procedure is split into two melting procedures for the other BMGs. The activation energy decreases with increasing sensitivity index β for the studied Zr-based BMGs. The plastic strain εp is in the region of 0.2%–19.1% for these Zr-based BMGs. Both yield strength σy and fracture strength σf are smallest for Zr55Al8.9Ni7.3Cu28.8 BMG whose εp is largest among all studied Zr-based BMGs and reaches up to 19.1%. In addition, the mechanism for the large difference of the plasticity among the studied Zr-based BMGs is also discussed.

文章分析了工程应用型本科院校机械类专业人才培养产教融合的背景与现状、以湖南理工学院机械学院为例,从培养方案及课程体系、实践教学体系、"双师型"教学团队、产教融合共赢途径等四个方面对其机制进行了研究与实践.对用人单位、毕业生进行调查结果显示,改革效果良好.

增材制造技术的发明和应用为机械行业的发展提供了广阔空间,为满足这一趋势,机械制造业对工程创新型人才的需求也日益迫切.湖南理工学院机械工程学院通过构建“宽口径、柔方向”的课程体系,采用校企共建创新工作室、人才培养基地等形式,开展机械工程创新人才培养,通过实施“面向工程、项目对接、阶梯推进”的工程创新能力培养新模式,不断完善创新工作室的建设和管理,实现了教师队伍建设水平、学生培养质量的双提升.

The isothermal section of the Cu-Co-Nb ternary system at 1198 K has been investigated by means of diffusion triple together with electron probe microanalysis technique. Series of tie lines and tie-triangles have been determined and the isothermal section at 1198 K has been establishedi¼Œand four three-phase fields have been figured out. Namely, (Nb)+(Cu)+Co7Nb6, (Cu)+Co2Nb+Co7Nb6, Co2Nb+Co3Nb+(Cu) and Co3Nb+(Co)+(Cu) existing in the present isothermal section. In present work Co3Nb and Co7Nb2 were disposed as only one phase Co3Nb. It is found that the solubility of Cu in Co3Nb, Co2Nb and Co7Nb6 are only up to 5.70, 5.80 and 4.20 at.% Cu, respectively. The range of homogeneity of Co7Nb6 and Co2Nb is 44.7 to 48.0 at.% and 25.0 to 29.6 at.% Nb, respectively. The Co3Nb is line compounds.

创新人才的培养是高等学校面临的永恒的重要课题之一，如何培养创新人才是高等院校尤其是地方性高等院校的难题，本文针对地方性高等院校的创新人才的培养的制约因素进行了剖析，提出了相应的解决措施和途径。

Effect of network structure on plasticity and fracture mode of Zr–Al–Ni–Cu bulk metallic glasses (BMGs) was investigated. The microstructures of transversal and longitudinal sections were exposed by chemical etching and observed by scanning electron microscopy (SEM). The mechanical properties were examined by room-temperature uniaxial compression test. The results show that both plasticity and fracture mode are significantly affected by the network structure and the alteration occurs when the size of the network structure reaches up to a critical value. When the cell size (dc) of the network structure is ∼s3 μm, Zr-based BMGs characterize in plasticity that decreases with increasing dc. The fracture mode gradually transforms from single 45° shear fracture to double 45° shear fracture and then cleavage fracture with increasing dc. In addition, the mechanisms of the transition of the plasticity and the fracture mode for these Zr-based BMGs are also discussed.

This paper analyzes specialized English teaching present situation of the new undergraduate colleges,the characteristics and course target of the course.It is necessary for specialized English teaching to put forward concrete teaching plan and goal,choose suitable teaching materials,reform teaching methods and means,and strengthen the construction of teaching staff.Based on undergraduates and Employer,the reform effect is good.

Phase formation, glass forming ability, mechanical and thermal properties of Cu 50 Zr 50− x Al x (0⩽ x ⩽11.0) glass forming alloys were systematically investigated. The results show that Cu 50 Zr 47 Al 3 alloy has the best glass forming ability (GFA), lowest fragility index ( m ) and highest fracture strength. There are B2 CuZr and B19′ CuZr phases for Cu 50 Zr 50− x Al x (0⩽ x ⩽5.0) alloys. B2 CuZr phase disappears and two new phases (Cu 10 Zr 7 and CuZr 2 ) appear when 5.05.0). Cu 50 Zr 50− x Al x (0⩽ x ⩽4.0) alloys are off-eutectic compositions while near-eutectic compositions for Cu 50 Zr 50− x Al x (5.0⩽ x ⩽11.0) alloys. The E g , E x , and E p decrease with increasing sensitive factor ( β ) for the studied Cu-based alloys characterized in the room-temperature brittleness. The dependence of the phase formation and GFA on the Al content is discussed.

探索社会急需的高技能应用型人才的培养途径与方式方法,培养高素质应用型人才,一直是高等院校及企业需要迫切解决的核心问题.本文以湖南理工学院机械类专业本科应用型人才培养为例,结合机械类专业建设情况,介绍通过建立校企合作长效机制,深化实践内涵的一系列校企合作人才培养改革模式,探索本科应用型人才培养实施的思路与途径.

Mechanism, condition and characteristics for the formation of the network structure in a group of Zr-Al-Ni-Cu bulk metallic glasses (BMGs) were investigated. The results show that the constituent segregation and/or the symplastic growth would be the mechanisms for the formation of the cell structure in the present Zr-Al-Ni-Cu BMGs. The cell structure can be easily obtained for the glass forming alloys whose compositions locate nearby the eutectic point. The shorter the distance is from the eutectic point, the larger the cell and the thicker the cell wall of the network structure will be. The present investigation would provide useful information for the development of the BMG with the network structure.

Glass forming ability, thermal, electrical and mechanical properties of Cu50Zr40Ti10-xNix (0 <= x <= 4.0 at%) glass forming alloys were systemically investigated. It is found that the critical dimension of the present Cu-based glass forming alloys firstly increases with increasing Ni content, then decreases when Ni >2.0 at%. Ni addition results in the increase of the electrical resistivity and the thermal conductivity. The glass transition temperature increases with increasing Ni content for the present Cu-based BMGs at all studied heating rates. However, there are complex correlations for the other characteristic temperatures, crystallization enthalpy and activation energy with the Ni content and heating rate, respectively. The plastic strain firstly increases with increasing Ni content, then decreases when Ni >2.0 at%. Both yield strength and compression strength nearly increase with increasing Ni content. The plastic strain increases with decreasing m in the range of 0 <= Ni <= 2.0 at% and 2.0 <= Ni <= 4.0 at% for present Cu-based BMGs. The m linearly decreases with increasing d(c) for the present cu-based BMGs. The corresponding mechanisms are also investigated. (C) 2014 Elsevier B.V. All rights reserved.

本文以湖南理工学院机械类专业本科应用型人才培养为例，首先介绍校企合作长效机制的建立过程，探索了高校机械类专业校企合作人才培养模式的创新思路与途径。

Laser-assisted machining (LAM), defined as a hot machining process, combines laser technology with traditional machining method for improving material removal rates. It can reduce the cutting force and improve the processing efficiency of hard-to-wear materials, especially engineering ceramics. To enhance the processing precision of alumina ceramic turning, this article presents the results of an experimental study of a two-step laser-assisted turning process including laser-induced thermal cracking and turning. This study investigates the distribution of microcracks for different process parameters. Comparing with the results, it is observed that the mechanism of crack formation and crack types are different. The cracks are caused by thermal stress and mechanical stress, separately. Based on uniform design, a back propagation neural network model is developed to map the complex nonlinear relationship between process parameters and processing requirements. The results show that the model is an effective tool for predicting the integrity of the machined ceramic surface.

地面清洁装置的最重要的部件是清扫部件,通过改进清扫部件的性能,可以提高地面清洁装置的工作的效率,可大大减轻地面清扫工作者的劳动强度,提高地面清洁效率.就目前机械车间清洁工作的情况设计一款集清扫、收集、转运为一体的地面清洁装置,清扫部件由清扫机构和上料机构等组成.该清扫部件价格便宜,工作可靠,操作简单,效果好,同时其外型简单美观,结构合理,适用性强.且该清扫装置在清扫过程中无二次污染,能够很方便的和其他设备组合使用,节约成本,推广性好.

Silicon nitride ceramics are extremely difficult and time-consuming to machine with conventional methods, such as turning and grinding. Laser-assisted machining has been a field of extensive research during the past decade, as it is a promising solution to enhance the machinability of many difficult-to-cut materials, including silicon nitride ceramics. To enhance the processing precision of silicon nitride ceramic grinding, this paper presents an experimental investigation of a two-stage laser-induced wet grinding (LIWG) process, including laser-induced thermal cracking and wet grinding. Specifically, the differences in the grinding force, grinding force ratio and surface roughness obtained for LIWG and conventional grinding (CG) conditions are compared and discussed. The normal and tangential grinding forces for LIWG condition were lower than for the CG condition with a maximum reduction of 70.4% (83.3%) for the maximum average normal (tangential) grinding forces. The values of the force ratio for the CG condition and LIWG condition were in the range of 3.7–5.5 and 6.5–11.5. Little improvement was achieved, and the surface roughness values are considerable for both conditions.

The isothermal section of the Co-Ti-V ternary system at 873 K has been investigated by means of diffusion triple together with electron probe microanalysis technique. Series of tie lines and tie-triangles have been determined and the isothermal section at 873 K has been established, and nine three-phase fields have been figured out. It is found that VCo3, VCo, TiCo3, TiCo2(h), TiCo2(c) and TiCo have range of homogeneity at 873 K, and the V3Co and Ti2Co are line compounds. The solid solubility of Ti in VCo3, VCo and V3Co is about 5.2 at.% Ti, 8.8 at.% Ti and 6.9 at.% Ti, and that of V in TiCo3, TiCo2(h), TiCo2(c), TiCo and Ti2Co is about 6.1 at.% V, 3.7 at.% V, 3.0 at.% V, 9.3 at.% V and 6.6 at.% V, respectively. (C) 2014 Elsevier B.V. All rights reserved.

An artificial neural network (ANN) model was developed for simulating and predicting critical dimension dc of glass forming alloys. A group of Zr-Al-Ni-Cu and Cu-Zr-Ti-Ni bulk metallic glasses were designed based on the dc and their dc values were predicted by the ANN model. Zr-Al-Ni-Cu and Cu-Zr-Ti-Ni bulk metallic glasses were prepared by injecting into copper mold. The amorphous structures and the determination of the dc of as-cast alloys were ascertained using X-ray diffraction. The results show that the predicted dc values of glass forming alloys are in agreement with the corresponding experimental values. Thus the developed ANN model is reliable and adequate for designing the composition and predicting the dc of glass forming alloy.

In order to enhance the grinding precision of alumina ceramic, this paper presents the results of an experimental study of a two-step laser-assisted wet grinding process including laser-induced thermal cracking and wet grinding. In particular, the differences in grinding force, grinding force ratio, and surface finish obtained under laser-assisted wet grinding (LAWG) and conventional grinding (CG) conditions are compared and discussed. It is found that the normal and tangential grinding forces for LAWG condition are lower than for CG condition. The higher material removal rates on LAWG condition can be achieved. The average grinding force ratios for CG condition are lower than for LAWG condition. The surface roughness values are considerable in both conditions, and the improvement for surface roughness is not obvious. This is attributed to the final grinding pass through the unaffected parent material.