一种无镍奥氏体不锈钢的组织与性能

对用中频感应炉熔炼，电渣二次重溶工艺制备的Fe-Cr-Mn-C-N无镍奥氏体不锈钢进行了组织与性能测试。结果表明，该钢为单相奥氏体，平均晶粒直径为85μn，钢中成分均匀，未发现元素偏析；该钢具有较好的强度和韧性：σb=1205MPa，σ0.2=632MPa，δ5=39％，HV=296。     

高职机械设计基础课程创新教育初探

《机械设计基础》课程是高职机类学生的主干课程 ,实施创新教育已成为该课程建设和改革的重点。创新教育必须贯穿于教学的全过程 ,并通过各个教学环节予以落实 ,建立新的启发性和综合性的课堂和实验教学手段 ,进行机械创新设计训练 ,以达到培养学生的创新意识、提高学生的创新能力和应用能力的教学目标     

聚丙烯纤维混凝土或砂浆的施工及力学性能

进行了聚丙烯纤维掺入量对混凝土及砂浆的操作性能及力学性能影响的试验研究。试验表明 ,混凝土及砂浆中聚丙烯纤维掺入量的变化 ,将对混凝土及砂浆的用水量、砂率、劈裂抗拉强度以及变形性能等方面产生影响。在保证混凝土及砂浆的施工操作性能前提下 ,找出最佳掺入量及配合比。     

Martensite transformation, mechanical properties and shape memory effects of Ni-Mn-In-Mg shape memory alloys

The martensite transformation(MT), mechanical properties and shape memory effect(SME) of(Ni_(50)Mn_(35)In_(15))_((1-x))Mg_x(x = 0%, 0.08%, 0.3%, 0.6% at%) alloys were comprehensively investigated. The results showed that due to Mg doping the MT temperature shifted to higher temperatures and a worm-like secondphase precipitated at grain boundaries and inside the grains. With increasing Mg content, the amount of precipitates gradually increased, the thermal hysteresis was almost invariant, and the SME was not obviously affected at 3% pre-strain, even when the volume of the second phase reached up to 28.75%. Compressive stress and strain experiments showed that both the strain and strength of the Ni-Mn-In-Mg alloys were improved substantially(by 46.9% and 53.4%, respectively, at x = 0.6%) compared with those of the pure Ni_(50)Mn_(35)In_(15) alloy; this effect is nearly the same as that achieved by the directional solidification method. Because Mg is nonmagnetic, the magnetization difference of the alloy with Mg doping is much lower than that of the alloy without Mg doping. Overall, the results confirm that adding a small amount of Mg is a potentially viable method for improving the mechanical properties of Ni-Mn-In alloys without adversely damaging their functional properties.     

不同因素对机械弹性智能车轮加速度信号的影响

为了研究不同滚动工况对机械弹性智能车轮加速度信号的影响,采用有限元分析方法研究速度、附着系数、载荷对接触应力和加速度信号的影响以及车轮不同位置的加速度信号的差异性。结果表明：速度和地面附着系数对法向接触应力分布影响不大;路面附着系数增大导致摩擦应力分布的不均匀性增加,载荷增大导致接地区域接触应力最大值增大。车轮速度增大,加速度峰值幅值增大,加速度峰值时间间隔减小;载荷增大,加速度峰值时间间隔增大;纵向附着系数功率谱能对地面附着系数进行区分;輮轮中间加速度信号更适合用于侧偏特性研究,通过侧向加速度信号积分得到侧向位移,可用于侧偏角估算。     

转盘式双筒激光熔覆送粉器的结构设计及应用

针对传统激光熔覆送粉器存在结构复杂、易堵塞且送粉不均匀不稳定等问题,基于机械力学和气体动力学原理,设计了一款转盘式双筒激光熔覆送粉器的结构。通过对送粉器的结构以及传动原理的分析,利用绘图软件进行气路设计和机械结构设计。气路设计是送粉装置中气体输送管道大小的确定和管道位置的安排。机械结构设计是零部件的设计,主要包括转盘、料筒、进出料口、进气口、腔体、传动系统、搅拌系统等。结果表明,此次设计的送粉器在粉末运输过程中具有连续、均匀、稳定、易于控制等方面的优良性能,在激光熔覆作业过程中,利用此送粉装置可获得质量较高的熔覆层。     

普通V带传动的多目标优化设计

<正>本文介绍了普通V带传动的多目标优化设计方法,所追求的目标是轴压力、中心距最小和皮带根数最少,采用线性加权的方法进行优化设计,其加权因子用各分目标的变异系数确定。可供机械设计人员设计普通V带传动时参考。     

竹材胶合板的研究——Ⅲ.竹材胶合板的物理和机械性能

<正>试验结果证明,竹材胶合板是一种吸水率低、膨胀率小、尺寸稳定、强度高、刚性好、阻燃性能好的工程结构材料。其强度高于当今其他结构板,也可与高强度的木材相媲美。可在车厢、建筑、机械等工业部门广泛应用。     

Simulation Model of Mechanical Properties of Point - Bonded Nonwovens

A computer model for studying the mechanical properties of point - bonded nonwovens is established. The simulation tensile curve of a nonwoven fabric may be obtained based on relaxation procedure when the mechanical properties of fibers, the arrangement of bond points in the fibrous web and specimen size are inputted into the computer. Relaxation method and relevant algorithms of computer simulation are described in detail. The validity of the model is also demonstrated.     

Binder- and conductive additive-free Ga2O3 nanowires as a self-healing anode for lithium storage

High-capacity anode materials have stimulated much attention to developing high-performance lithium-ion batteries. However, high-capacity anode materials commonly suffer from the pulverization matter that greatly hinders their practical applications, especially in terms of the high proportion of active materials. In this work, a Ga₂O₃nanowire electrode is synthesized by thermal evaporation and immediately used as an anode without the aid of binders and conductive additives....