杂质泵白口铸铁件冒口及浇注系统设计

叙述了杂质泵白口铸铁件冒口设计程序和浇注系统的计算方法，以R．C．Creese的计算冒口的公式为基础，以杂质泵白口铸铁件为例，说明求解冒口尺寸的过程。介绍常用的几种强化冒口补缩的措施：采用保温冒口，浇注系统通过冒口，以及一个冒口补缩多个铸件等，用所介绍的方法设计的保温冒口，生产的铸件致密性良好。     

熔模铸件冒口当量热节设计法

将当量热节概念应用于冒口设计，提出了冒口的当量热节设计法。在当量热节直径根据简化后的铸件截面尺寸通过图表确定后，可以计算出冒口颈直径、冒口直径、冒口体积和冒口高度。冒口的当量热节设计法，概念直观，计算简单。     

应用压边浇冒口生产有色合金铸件

根据“顶注优先、冒口靠边”的均衡凝固的工艺设计原则，改进了铜、铝等有色合金铸件的浇口和冒口工艺。合理使用压边浇冒口，有效地提高了有色合金铸件的质量和工艺出品率。     

车用柴油机蠕墨铸铁缸盖铸造工艺探讨

采用底注或分型面侧注，顶置冷冒口、砂型、砂芯多开气眼等传统工艺方法不可能彻底消除缩孔、缩松、气孔和气缩孔等常见缺陷，是缸盖生产长期废品率高的主要原因。采用顶置热冒口，扩大冒口覆盖范围，铁液通过冒口进入型腔，提高浇注液流压力，利用冒口铁液压力进行液态补缩和阻止气体进入热节，是消除缩孔、缩松、气孔和气缩孔的有效措施。     

球铁钳体铸造缺陷与对策

球铁钳体铸件曾发生缩松、夹渣、粘砂等缺陷，通过采用热冒口取代冷冒口、增设溢流集渣冒口、提高浇注温度和改进覆膜砂等措施，上述铸造缺陷全部得到解决。     

消失模铸造冒口工艺改进的探讨及应用

在消失模铸造中为避免铸件产生气孔、夹渣、冷隔等缺陷，着重探讨将冒口改为大气压力冒口，并填入覆盖剂，使冒口除起补缩作用外，还有提高铸件保温、排气和集渣的作用，从而提高了铸件的成品率，并推荐了覆盖剂、砂芯基本材料和工艺配方案。     

保温冒口在铸造生产中的应用

保温冒口的作用是通过延长冒口凝固时间来提高冒口的补缩效率。介绍了两种保温冒口材料的配比。对两种保温冒口与普通冒口的凝固时间进行了测量对比，结果说明前者的凝固时间比后者长。在大型铸钢齿圈上使用保温冒口，可以使工艺出品率由57％提高到69％，并减少了冒口切割费用。     

计算机冒口设计系统的开发

基于UG平台,开发了铸造CAD/CAE铸钢件冒口设计系统。结合实际生产铸件大小和种类,建立了用户冒口库,根据铸造工艺手册及其冒口设计标准建立标准冒口库。通过设计计算、UG/API编程、冒口参数录入、对比分析等确定冒口尺寸、类型。通过冒口自动分配与组装、工艺模拟分析完成冒口设计工作。     

保温冒口在有色金属铸造炽的研究与应用

研究了保温冒口在有色金属铸造中的作用。结果表明：采用膨胀珍珠岩和空心微珠等材料，按三种方案配比，配以适当的干燥工艺，可以使冒口体积缩小５０％，保温冒口金属的凝固时间延长１－３倍，工艺出品率提高１０％－２５％。     

飞轮铸件无冒口铸造工艺

分析了飞轮铸件无冒口铸造工艺的可行性。试生产结果表明，采用无冒口工艺浇注的铸件组织均匀致密，且无缩孔等缺陷。     

降低开式模锻锻靠力的工艺措施

根据对开式模锻变形过程的理论分析，论述了几种主要工艺参数对开式模锻锻靠力的影响，提出降低开式模锻锻靠力的主要工艺措施。实践证明，这些工艺措施是行之有效的。     

Ultrasonic evaluation of TiAl and 40Cr diffusion bonding quality based on time-scale characteristics extraction

To solve the problem of ultrasonic pulse-echo method in the evaluation of kissing bond and unbond in TiAl and ⁴⁰Cr diffusion bonding, a characteristics extraction algorithm was proposed. The algorithm was based on continuous wavelet transform to convert ultrasonic TiAl and ⁴⁰Cr diffusion bonding interface signals into time-scale domain. The ultrasonic tests were performed by an ultrasonic C-scan imaging system using a 10 MHz focused transducer. The time-scale amplitude and phase of the interface signals were calculated and analyzed to distinguish the kissing bond and the unbond from the perfectly bonded interface. The kissing bond can be detected by the scale-dependent amplitude combined with phase variation and the unbond can be measured by the opposite phase. The amplitude and phase characteristics were extracted to reconstruct the amplitude and phase characteristics images for TiAl and ⁴⁰Cr diffusion bonding specimens evaluation. The amplitude and phase characteristics images are effective in the evaluation of bonding quality.     

搅拌摩擦焊接缺陷的补焊方法

搅拌摩擦焊接方法在某些条件下也会造成焊接缺陷的产生,其中对接头性能有显著影响的缺陷包括沟槽、孔洞和未焊合.针对这三种类型的缺陷,用搅拌摩擦焊接方法进行补焊,以此研究补焊接头的焊缝成形和力学性能.结果表明,采用搅拌摩擦补焊方法能够消除沟槽、孔洞和未焊合等搅拌摩擦焊接缺陷;在优化的补焊工艺参数下,能够获得焊缝成形良好的补焊接头,其性能与优质原始接头的性能相当;补焊接头在拉伸测试中均在焊缝的后退侧发生断裂,拉伸断口具有明显的韧窝特征.     

双辊铸轧不锈钢薄带的三维有限元数值模拟

采用三维有限元法模拟了双辊铸轧不锈钢过程的流热耦合问题,分析了铸轧速度以及浇铸温度对熔池内流场、温度场的影响,给出了凝固过程中熔池与铸轧辊之间的热流密度变化趋势及凝固终子位置随浇铸温度的变化规律,模拟结果与实验数据比较吻合。     

Measurement of the ultrasonic nonlinearity of kissing bonds in adhesive joints

This paper presents a study of the detectability of kissing bonds in adhesive joints using an ultrasonic inspection technique to measure nonlinearity. Kissing bonds are defined as adhesive bonding defects in which the adhesive and the substrate are not fully bonded together but are in some way connected, for example, through contact between disbonded surfaces or through coupling via a very thin layer of contaminant. The result is a region that exhibits reduced normal or shear stiffness and is difficult to detect using conventional non-destructive testing techniques. It is hypothesised that when an ultrasonic wave of large magnitude propagates through the kissing bond area, the system will behave nonlinearly. This hypothesis is the starting point for this paper, and it is tested by measuring the degree of nonlinearity exhibited by perfectly and imperfectly bonded specimens. Perfectly disbonded adhesive joints are tested over a range of compressive loads from an initial zero-load ‘open’ condition to a final highly loaded ‘closed’ condition and the degree of nonlinear behaviour measured. It is shown that adhesive joints exhibit significant nonlinearity under light compressive loads and that the level of nonlinearity decreases rapidly with compressive load. Good agreement is also observed between experimental results and a nonlinear spring model of the adhesive joint, based on its quasi-static interfacial stiffness.     

High-Speed Friction Stir Welding of T6-Treated B_4Cp/6061Al Composite

T6-treated 20 wt% B_4 Cp/6061 Al sheets were joined under welding speeds of 400–1200 mm/min by friction stir welding(FSW) with a threaded cermet pin. The macro-defect-free FSW joints could be achieved at high welding speeds up to 1200 mm/min, but larger plunge depth was required at the welding speeds of 800 and 1200 mm/min to eliminate the tunnel defect. In the nugget zone(NZ) of the joints, the B_4 C particles were broken up and uniformly redistributed. The NZ exhibited lower hardness than the base metal(BM), and the hardness value almost did not change with increasing welding speed, attributable to the dissolution of precipitates. Compared with the BM, the joints showed lower tensile strength. As the welding speed increased from 400 to 800 mm/min, the joint efficiencies were nearly the same and up to ～ 73%. When the welding speed increased up to 1200 mm/min, the tensile strength significantly decreased, due to the occurrence of kissing bond defect at the bottom of the NZ. With increasing welding speed, the fracture location of the joints transferred gradually from the heat-affected zone to the NZ due to the kissing bond defects.     

Production technique of vermicular graphite iron cylinder head of vehicle diesel engine

The 25 years＇ production and application have proved that vermicular graphite iron cylinder heads with vermicularity ≥50% satisfy the machinability and performance demand of diesel engine. The method, in which using cupola-induction furnace duplex melting and pour-over process with rare earth-ferrosilicon or rare earthsilicon compound as vermJcularizing alloy plus rare earth-magnesium-ferrosilicon as stirring alloy, is an optimal vermicularizing process for obtaining satisfied vermicularity. Using top kiss risers, enlarging kissing areas and expanding covering width and making ingates to freeze earlier are the effective measures to eliminate shrinkage, blowhole and oxide inclusions in the vermicular graphite iron cylinder heads.     

开式模锻型腔充满阶段和锻靠阶段的变形力

本文从开工模锻锻件成形过程的金属流动特点来描述变形力分布的变化，推导出型腔充满阶段和锻靠阶段的变形力分布及二者之间的合理对应关系。     

TiAl/40Cr扩散焊接头强度评价与预测

为了解决界面回波幅度均值无法评价异种材料扩散焊接头强度的问题,文中提出一种接头强度评价与预测方法.该方法基于二叉树支持向量机构建界面缺陷的识别模型,根据识别结果计算界面的焊合率,建立焊合率与抗剪强度的关系.采用线性拟合的方法获得抗剪强度的经验公式,用于预测接头强度.结果表明,构建的缺陷识别模型可以有效地识别出扩散焊界面未焊合、弱接合和微孔缺陷,焊合率与接头抗剪强度具有相关性,抗剪强度随着焊合率的增加而增加.实现了接头强度的预测,预测强度与实测值吻合较好.     

蓄电池槽盖注射模设计

通过对蓄电池槽盖的工艺分析,介绍了该槽盖注射模的整体结构及设计要点,研究了模具成型、顶出等过程,分析了双向分型对吻型芯和活动型块的结构特点,提出了一种较为简化的的模具结构,实现了槽盖的顺利成型,解决了具有45°倾角Ф12mm通孔和内侧壁凹槽的成型、脱模困难等问题。