实体轴承保持器等温挤压工艺及模具

介绍了实体轴承保持器的生产现状 ,研究了保持器的等温挤压成形工艺 ,并介绍了相关模具设计。结果表明等温挤压工艺是十分经济有效的。     

轴承保持器等温挤压工艺及模具

介绍了实体轴承保持器的生产现状，研究了保持器的等温挤压成形工艺，并介绍了相关模具设计。结果表明等温挤压工艺是十分经济有效的。     

轴承保持架筒形坯件挤压铸造成形工艺及组织性能研究

采用直接挤压铸造成形工艺来生产Al-Cu系合金高速机床主轴轴承保持架筒形坯件，试验研究了其工艺参数对该铸件组织及力学性能的影响，从而确定出挤压铸造简形件合适的工艺参数。     

机械工业“十二五”主攻重点领域之基础工艺及技术

(1)基础工艺重点推进铸造、锻压、焊接、热处理和表面工程等基础工艺的技术攻关,为高端装备的自主创新提供强有力的工艺支撑,积极推进绿色加工工艺及装备的推广应用。大力发展高强度轻质合金零件精密铸造技术,铸造工艺清洁技术,新型绿色铸造工艺技术;铸(锻)造—热处理连续工艺技术,铸造节能技术;精密冲压技术,挤压—弯曲复合成形技术,轴承冷辗扩技术,超     

凸轮轴轴承盖挤压铸造工艺及数值模拟研究

通过对轴承盖挤压铸造工艺分析,确定了成形工艺方案,运用ProCAST对ADC12铝合金汽车凸轮轴轴承盖的直接挤压铸造成形过程进行了数值模拟,并对合金液的充型及凝固过程进行了可视化观察,预测充型及凝固过程中的缺陷。模拟结果表明,铸件的充型及凝固过程合理,有效的减小了缺陷的产生。并通过试制生产验证了该成形方案的可行性,为实际生产提供了理论依据和指导。     

基于ObjectARX的铜合金轴承实体保持架等温挤压模CAD系统开发

等温超塑挤压成形技术开辟了铜合金轴承实体保持架加工的新途径。在此新技术的基础上，利用vc^ 6．0和ObjeetARX开发了一套铜合金轴承实体保持架挤压模CAD系统软件，大幅度缩短了保持器系列产品的开发周期，并提高了产品设计效率和设计水平。     

挤压铸造汽油发动机主轴承盖通过技术鉴定

由湖南省长沙市科委主持的挤压铸造工艺技术鉴定会于1987年7月9日至10日于长沙县板仓通过。参加会议的代表有22人。 会议代表认为:将挤压铸造工艺应用于CS492-1A汽油机主轴承盖是先进的、成功的,它消除了常见的铸造缺陷、组织致密     

ObjectARX铜合金轴承实体保持架等温挤压模CAD系统开发中的应用

等温超塑挤压成形技术开辟了铜合金实体保持架加工的新途径。在此新技术的基础上，利用VC^ 6．0和ObjectARX开发了一套铜合金轴承实体保持架挤压模CAD系统软件，大幅度缩短了保持器系列产品的开发周期，并提高了产品设计效率和设计水平。     

挤压铸造锻模用5CrNiMo合金钢的熔炼技术

采用挤压铸造工艺生产5CrNiMo合金钢锻模,具有良好的应用前景;通过工程实践,总结了挤压铸造用5CrNiMo合金钢的熔炼工艺要点,为发展锻模挤压铸造生产提供实际依据。     

挤压铸造实用技术研究

给出了直接式挤压铸造模具和双分型面挤压铸造模具设计技术要点;论述了挤压铸造技术方案的选择原则.实践证明,获得合格挤压铸造件的首要条件是设备性能稳定可靠、工艺方案正确、模具结构合理;必要条件是各工艺参数间要相互协调,应根据生产中条件的变化和各工艺参数之间相互影响调整主参数.     

镁合金挤压铸造研究进展

对国内外镁合金挤压铸造研究现状进行了综述,对镁合金挤压铸造的研究意义进行剖析,就镁合金挤压铸造的设备、方法及生产工艺进行了综合和比较,并就研究方向和发展前景进行预测和展望,为镁合金挤压铸造的进一步发展提出见解和主张.     

挤压铸造制备半固态AZ61镁合金的组织演变及力学性能(英文)

采用挤压铸造后直接二次重熔的方法制备半固态AZ61镁合金。首先通过挤压铸造预成形铸态AZ61镁合金,以获得细小的枝晶;然后在半固态区间进行二次重熔,细小的枝晶演变成球状晶,完全球化的晶粒被液相均匀包裹。研究结果表明:通过挤压铸造预成形的铸态AZ61镁合金与传统铸造预成形的铸态AZ61镁合金相比,在相同的二次重熔条件下,挤压铸造预成形的铸态AZ61镁合金获得更细小的半固态组织。此外,挤压铸造加上二次重熔触变成形的AZ61镁合金,力学性能优于传统铸造后二次重熔触变成形的AZ61镁合金。     

Improvement of microstructure,mechanical properties,and corrosion resistance of WE43 alloy by squeeze casting

The WE43 magnesium alloy was prepared by squeeze casting, and the influence of squeeze casting parameters on mechanical properties and corrosion resistance was studied and compared with gravity casting. The gravity cast WE43 alloy shows uneven grain size distribution, and some grains even greater than 90 µm. While, the grain size of the squeeze cast WE43 alloy is mainly distributed in 20–50 µm. The Mg₁₂Nd₂Y phase morphology changes from large lamellar to strips after squeeze casting, whereas Mg₂₄Y₅ phase exhibits no obvious change. The yield strength, tensile strength, and elongation of the gravity cast WE43 alloy are 127 MPa, 157 MPa, and 6%, respectively, and 145 MPa, 193 MPa, and 9.1% for squeeze cast alloy. For the squeeze cast WE43 alloy, the average corrosion rate is 0.6056 mm·year⁻¹ according to immersion test results, and according to electrochemical measurements, the corrosion current density is 78.13 µA·cm⁻², which is better than that of the gravity cast WE43 alloy. Compared with gravity casting, the grains and second phase of the WE43 alloy by squeeze casting are refined, and the mechanical properties and corrosion resistance are improved. This may expand the applications of the WE43 alloy.

     

挤压铸造方式对ZA43合金力学性能的影响

从合金液的流动和压力损失的角度 ,研究了两种挤压铸造方式对ZA43合金力学性能的影响。结果表明 :冲头式挤压铸造使合金液反向充型流动 ,改善了ZA43合金的凝固条件 ,有利于补缩 ,且压力损失小。柱塞式挤压铸造虽然也加强合金液流动 ,但没有宏观的充型运动 ,且压力损失大。为获得高塑性ZA43合金铸件 ,柱塞式挤压铸造所需的比压比冲头式挤压铸造的大得多     

挤压铸造方式对ZA43合金力学性能的影响

从合金液的流动和压力损失的角度,研究了两种挤压铸造方式对ZA43合金力学性能的影响。结果表明:冲头式挤压铸造使合金液反向充型流动,改善了ZA43合金的凝固条件,有利于补缩,且压力损失小。柱塞式挤压铸造虽然也加强合金液流动,但没有宏观的充型运动,且压力损失大。为获得高塑性ZA43合金铸件,柱塞式挤压铸造所需的比压比冲头式挤压铸造的大得多。     

混合稀土和挤压铸造对ZL305合金组织和性能的影响

采用挤压铸造和重力铸造制备出不同混合稀土含量的ZL305合金,研究了混合稀土含量和挤压铸造对合金微观组织和力学性能的影响。结果表明,在重力铸造下,添加混合稀土对合金晶粒细化效果明显,当添加0.1%的混合稀土时,ZL305合金的综合力学性能达到最佳,抗拉强度增加到227.88MPa,伸长率为6.47%。相比重力铸造,挤压铸造成形的合金组织明显细化,并且合金铸态的抗拉强度和伸长率都明显提高。添加0.2%的混合稀土时,合金的抗拉强度和伸长率最佳,分别为302.35MPa和7.23%。经430℃×10h固溶处理后挤压铸造合金的性能显著提高。     

Effect of pressure on microstructures and mechanical properties of Al-Cu-based alloy prepared by squeeze casting

A new high-strength aluminum alloy with better fluidity than that of ZL205A was developed. The effect of applied pressure during squeeze casting on microstructures and properties of the alloy was studied. The results show that the fluidity of the alloy is 16% and 21% higher than that of ZL205A at the pouring temperature of 993 K and 1 013 K, respectively. Compared with permanent-mold casting, mechanical properties of the alloy prepared by squeeze casting are much higher. The tensile strength and elongation of the alloy are 520 MPa and 7.9% in squeeze casting under an applied pressure of 75 MPa, followed by solution treatment at 763 K for 1 h and at 773 K for 8 h, quenching in water at normal temperature and aging at 463 K for 5 h. The improvement of mechanical properties is attributed to the remarkable decreasing of the secondary dendrite arm spacing(SDAS) and eliminating of micro-porosity in the alloy caused by applied pressure.     

Effect of specific pressure on microstructure and mechanical properties of squeeze casting ZA27 alloy

The effect of specific pressure on the microstructure and mechanical properties of ZA27 squeezed castings with high height-to-thickness ratio was studied. The results of DTA and SEM show that at high specific pressure the eutectic reaction of squeeze casting ZA27 alloy is restrained, and the final solidified structure is (η+ε) phases instead of eutectic phase (β+η+ε). At the same time, the primary reaction is promoted in squeeze casting ZA27 alloy solidified at high pressure, and the fine microstructure is obtained with the increase of pressure. Al and Cu elements are homogeneously distributed in matrix of squeeze casting ZA27 alloy. The homogenously distributed high-density fine ε phase can effectively hinder dislocation motion, and then the strength and plasticity of squeeze casting ZA27 alloy are increased.     

The effect of casting temperature on the properties of squeeze cast aluminium and zinc alloys

Gravity casting and squeeze casting were carried out on an aluminium alloy with 13.5% silicon and a zinc alloy with 4.6% aluminium with different temperatures, 660, 690 and 720 °C for the former and 440, 460 and 480 °C for the latter. A top-loading crucible furnace was used to melt the alloys. The die-preheat temperatures used were 200–220 °C for the aluminium alloy and 150–165 °C for the zinc alloy. A K-type thermocouples with digital indicator were used to measure the die surface temperature and the molten metal temperature; while a 25 t hydraulic press with a die-set containing a steel mould was used to perform the squeeze casting with a pressure of 62 MPa. Tensile, impact and density tests were carried out on the specimens. It was found that casting temperature had an effect on the mechanical properties of both gravity cast and squeeze cast aluminium and zinc alloys. The best temperatures to gravity cast the aluminium alloy and the zinc alloy were 720 and 460 °C, respectively. For the squeeze casting of the aluminium alloy, the best temperature to use was either 690 or 660 °C; the former would give a better property at the top of the casting while the latter, at the bottom of the casting. However, for the squeeze casting of the zinc alloy, the best temperature was again 460 °C.     

挤压铸造比压对铜合金阀体性能的影响

指出了压力铸造及热挤压工艺生产铜合金阀体的缺点 ,阐述了挤压铸造工艺的特征 ,介绍了挤压铸造在燃气器具铜合金阀体上的应用 ,分析了比压对产品性能的影响