油塞座冲孔、翻孔复合模具设计

介绍了汽车薄板件的冲孔、翻孔复合模结构设计及其工作原理,给出了预冲孔坯料尺寸、冲孔力、翻孔力的计算方法以及冲孔、翻孔凸、凹模间隙值的选定,凸凹模材料选定及其热处理规范.     

精密圆形件冲孔倒角复合模

介绍了一种可以在一次冲压工序中，完成精密圆形件冲孔、倒角的复合模。分析了模具结构特点，对该类模具的设计具有一定参考作用。     

槽钢冲孔模

槽钢冲孔模西安仪表厂田亚仙１槽钢结构特点以图１所示１０号槽钢为例，其外形尺寸大，在斜面上响面）冲孔，定位难，料厚，所需冲裁力大，显然一般的冲孔模难以满足要求。如采用悬臂式结构，模具体积大，模具寿命短。为此，设计图２所示的模具结构，解决了上述难题。模具...     

非合金化管坯冲孔模使用寿命的研究

研究用非合金化奥氏体-贝氏体球铁取代铁素体-珠光体稀土镁钼球铁,提高管坯冲孔模使用寿命的可行性。研究结果表明:球化处理+二次孕育处理的冶炼工艺提高了管坯冲孔模的铸态性能;900℃奥氏体化3h、400℃等温处理3h及水+油的双液快冷的热处理工艺,在管坯冲孔模的工作层中得到了奥氏体-贝氏体组织。经冶炼、热处理后的奥氏体-贝氏体球铁冲孔模的力学性能得到提高,使用寿命延长。     

冲孔切断连续模设计

为了解决垫条零件在冲压生产中出现的问题，设计了一套冲孔切断连续模取代原落料冲孔复合模。介绍了冲孔切断连续模的结构及工作特点。     

小管冲孔模设计

介绍了在6.4mm管材上冲2mm小孔的工艺、模具结构及冲孔模工作过程 ,使用该冲孔模提高了生产效率 ,满足了产品的质量要求     

钢管无凹模冲孔模

介绍了钢管无凹模冲孔模的结构及与传统模具不同的结构要求,为冲压体系增加无凹模冲孔工艺提供了保证。     

制动踏板冲孔模的设计

介绍了某轿车制动踏板(厚板)冲孔模的设计，以及试模，改进过程及效果。     

G6膜片高速连续级进模设计

通过对G6膜片高速连续级进模的设计，介绍了高精密冷冲压模具的主要设计程序，并详细介绍了预冲孔、子模、落料复位等模具结构在高速连续级进模中的应用。该模具结构都经过实践的检验，模具运行状态平稳，生产的零件质量可靠。     

花纹钢板冲孔模结构

花纹钢板冲孔模结构开封机械厂王子操我厂有一产品零件（见图１），其材料为扁豆形花纹钢板Ｂ３／δ３。产品批量生产时，采用钻孔工艺不能满足生产要求，改为冲孔加工，但在花纹钢板凸、凹界面处冲孔时，冲头由于受单边载荷作用而产生弯曲，因此不能使用普通冲孔模结构。...     

热处理对TC21钛合金显微组织的影响

对TC21钛合金进行双重固溶+时效热处理,研究固溶冷却速率、温度对合金显微组织的影响。研究表明,初生α相形貌主要受一次高温固溶温度控制,高温固溶冷却速率对次生α相含量及长宽比有显著的影响。高的固溶冷却速率可以保留更多的亚稳定β相,从而在时效过程析出更多细小的次生α相,导致强度增加,塑性及韧性下降。二次低温固溶温度对合金后续的时效响应有显著的影响,高的固溶温度可以保留更多的β相,促使更多细小的转变α相在时效中析出;低的固溶热处理温度导致固溶残余β相相含量减小,时效敏感性降低。时效过程导致残余β相的分解,特别是大块亚稳定β相区。     

后热处理工艺对放电等离子烧结制备NdFeB磁体的影响

放电等离子烧结(SPS)技术是制备NdFeB合金材料的一种新型工艺方法。本文研究了后热处理工艺对放电等离子烧结制备NdFeB磁体磁性能的影响，同时考察了后热处理工艺对SPS NdFeB磁体微观组织结构和尺寸精度的影响。在适当的后热处理工艺条件下，得到了细晶高性能NdFeB磁体。结果表明可以通过后热处理进一步改善SPS烧结磁体的磁性能，论证了采用SPS技术制备近净成形的细晶高性能NdFeB磁体是完全可行的。     

Effect of post-heat treatment on the fatigue behaviour of a friction stir spot-welded Al–Mg–Si alloy

In this paper, the effect of post heat treatment on fatigue behaviour of friction stir spot welded Al–Mg–Si aluminium alloy was investigated. The microstructure of the weld zone was classified into two regions: stir zone (SZ) and mixed zone (MZ), where fine equiaxed grains due to dynamic recrystallization were observed. Two kinds of post heat treatment, namely aging and T6 treatment, were applied to the as-welded joints. The grains in the SZ and MZ were extremely enlarged only by T6 treatment, but some fine grains still remained near the boundary of MZ. Fatigue tests were conducted using lap-shear specimens at a stress ratio R = 0.1. Post heat treatments exhibited little influence on fatigue strength, but fatigue fracture morphology was dependent on both load level and post heat treatment. At high applied loads, fatigue fracture took place through the MZ in the as-welded and aged joints, while along the boundary of MZ in the T6 treated joint. At low applied loads, the fatigue crack initiated at the edge of the nugget and then propagated through the upper sheet in the as-welded joint, but the lower sheet in the aged and T6 treated joints. The dependence of fracture morphology on post heat treatment was attributed to the change of microstructures and hardness distribution around the nugget by post heat treatment.     

Effect of cyclic heat treatment on the microstructure and mechanical properties of W-Ni-Co alloys

Current generation heavy alloys with enhanced static as well as high strain rate properties are based on W-Ni-Co alloys. These alloys are subjected to a cyclic heat treatment to obtain fine tungsten precipitates in the matrix and to realise superior mechanical properties. The present study is focused on processing 92W-5Ni-3Co alloy using a post-sintering cyclic heat treatment to obtain fine tungsten precipitates in the matrix. As-sintered alloys and cyclic heat treated (in vacuum) alloys are then subjected to (i) vacuum heat treatment with oil quenching and (ii) nitrogen heat treatment with water quenching. A comparison has been drawn based on microstructural features and mechanical properties, between the alloys processed (i) with and without cyclic heat treatment and (ii) with oil and water quenching. This study thus helps in understanding the effect of cyclic heat treatment and quenching medium on the microstructure and mechanical properties of W-Ni-Co alloys.     

S590粉末高速钢的热处理工艺和应用

试验研究了S590粉末冶金高速钢的热处理工艺,测定了热处理后钢的硬度和晶粒度。结果表明,粉末冶金高速钢的热处理规律和淬硬性与普通高速钢基本相同,但粉末冶金高速钢的碳化物更为细小均匀,红硬性、抗压强度、耐磨性和热处理畸变等特性均优于普通高速钢。此外,还介绍了S590粉末冶金高速钢滚刀的应用。     

原位合成TiCp/Fe复合材料的组织和热处理性能研究

研究了热处理对TiCp/Fe复合材料组织和性能的影响。结果表明:热处理可以改变复合材料的基体组织,进而提高其硬度并改善韧性,调质处理得到最佳的强韧性配合。热处理对复合材料中初始TiC颗粒的形貌、分布、大小等没有明显的影响,但热处理过程中有二次TiC颗粒的析出,对提高复合材料的增强效果有一定作用。     

Heat treatment process of new NdFeB magnet prepared by spark plasma sintering

1　INTRODUCTIONTraditionallysinteredNdFeBmagnetcanmeettherequirementofdimensional precisionthroughpost machining ,whichusuallyresultsin 4 5 %ofma terialloss.Post machiningnotonlywastestherareearthresources ,butalsoincreasesthe productioncost .Moreover ,itisdifficulttopreparehomogeneousworkpieceswithlargedimensionandcomplicatedshapeduetosomeuncontrollablefactorsinthecon ventionalsintering process .Ontheotherhand ,al thoughthebondedNdFeBmagnethasbetterforma bilityanddimensionalprecision ,…     

Grain refinement in a cast high Nb containing TiAl alloy by heat treatment

The grain refmement of an as-cast Ti-46Al-8.5Nb-0.2W (atom fraction in %) alloy by the cyclic heat treatments was studied. The heat treatment scheme included a tempering at 1250℃ and cyclic tempering at 1000 and 1200℃ three times after solution treatment at the temperature above α phase transus followed by immediate fan cooling. The fine and homogeneous near-γ microstructure can be obtained by this heat treatment, which causes the breakdown of as-cast microstructure and prevents the anomalous growing of originalγ phase.     

热处理对TiC_p/Fe复合材料组织和性能的影响

研究了热处理对液态等温反应合成的TiCp/Fe复合材料的组织和性能的影响。指出热处理可以使在凝固过程中产生的少量TiFe2 和Fe3 C等相溶解消失 ,并得到一定数量的细小的二次TiC增强相。热处理过程能完全改变复合材料的基体组织。通过不同的热处理工艺 ,可以获得具有不同基体组织的复合材料 ,合金元素钼可有助于基体组织的调整。热处理过程对复合材料的性能也有较大的影响 ,二次TiC对基体的强化作用使复合材料的抗拉强度上升和冲击值下降     

Microstructure and mechanical properties of fine grained uranium prepared by ECAP and subsequent intermediate heat treatment

The microstructure and mechanical properties of fine grained uranium prepared by equal channel angular pressing (ECAP) and subsequent intermediate heat treatment were investigated systematically by the confocal laser scanning microscope (CLSM), electron backscatter diffraction (EBSD) and split Hopkinson pressure bar (SHPB). The results show that the initial coarse grained uranium was refined from about 1000 to 6.5 μm prepared by ECAP at 3 passes and subsequent heat treatment, and the corresponding dynamic yield strength increased from 135 to 390 MPa. For the ECAPed uranium samples, the relationship between grain size and yield strength could be described by classical Hall–Petch relationship, and the fitting Hall–Petch relationship for the fine grained uranium samples prepared by ECAP was drawn.