液锻连挤硅线石粒子/铝复合材料的摩擦磨损行为

采用液锻连挤成形工艺获得了一种新型硅线石颗粒增强LY12铝基复合材料,其性能可与常规热挤压件媲美。摩擦磨损性能测试表明:硅线石颗粒增强铝基复合材料具有优良的摩擦磨损性能,且其耐磨性能随粒子体积分数增加而增加。材料经液锻连挤后,硅线石粒子在强大三向压应力作用下嵌镶于基体内,粒子很难拉脱,承受摩擦力的作用时,硅线石粒子起支承作用,粒子硬度高,故使复合材料整体耐磨性能提高。

分层浇注-累积液锻成形大高径比制件界面的力学性能研究

通过 2A12液态铝合金分层浇注 -累积液锻成形大高径比工艺试验、扫描电镜和Instron万能材料试验机等手段 ,研究了成形的大高径比制件界面处的力学性能 ,总结除了工艺参数对界面处的力学性能的影响。研究结果表明 :采用分层浇注 -累积液锻成形大高径比制件的方法是完全可行的 ;浇注温度、模具预热温度、施加的压力、浇注层数和加压前停留时间是影响界面处力学性能的主要工艺参数 ;浇注温度为 74 0℃、模具预热温度为 4 80℃、施加的压力为 5 0 0kN (比压为2 18 4MPa)、浇注层数为 3层、加压前停留时间为 5s时界面处的力学性能最好 。

间接液锻工艺参数对制件质量影响的研究

对间接式液态模锻工艺参数进行了系统研究，论述了液锻中各参数间的相互联系，给出了几个重要工艺参数的选取原则．

陶瓷粒子/铝板坯液锻连挤复合成形及轧制基础研究

对陶瓷粒子向铝液或铝粉混合过程机制和均匀性进行了研究，发现搅融混合实用性强，均匀性差，而原位反应法和粉末混合法能获得均匀浆料或粉末体。自行设计和制造了液锻连挤和固液挤压板坯的实验装置，进行了不同类型混合粉挤压成形的研究，从而揭示了液锻连挤和固液挤压工艺的实质，使其获得的板坯具有较好的塑性。再轧制实验，获得了不同开轧温度和轧制压下量对组织性能影响数据。搅融混合硅线石颗粒与ＬＹ１２，经固液挤压或液态模锻加工连杆瓦和轴瓦，以替代锡青铜，并通过实际考核，具有明显降噪。

消失模液锻中气隙压力和气流速度的计算分析

通过计算分析了消失模液锻制备颗粒增强金属基复合材料中,附带的增强颗粒泡沫载体与金属液作用后产生的气隙压力和气流速度,然后在消失模液锻TiC/ZG270-500实验中测量气隙压力和气流速度值,并探讨液锻工艺参数对气隙压力和气流速度的影响规律.实验结果表明:气隙压力和气流速度随充型速度、浇注温度、内浇口与排气孔横截面积比呈递增趋势,但均不随成形压力变化.此外,气流速度还随排气孔与型腔横截面积比增大而增大,气流速度随工艺参数变化趋势较平缓.

分层浇注-累积液锻成形大高径比制件界面结合研究

通过 2 A12液态铝合金分层浇注 -累积液锻成形大高径比工艺试验 ,用扫描电镜和 Instron万能材料试验机等手段 ,研究了成形的大高径比制件界面结合问题。研究结果表明 :采用分层浇注 -累积液锻成形大高径比制件的方法是完全可行的 ;浇注温度、模具预热温度、施加的压力、浇注层数和加压前停留时间是影响界面处力学性能的主要工艺参数 ;浇注温度为 740℃、模具预热温度为 480℃、施加的压力为 5 0 0 k N(比压为 2 18.4MPa)、浇注层数为 3层、加压前停留时间为 5 s时界面处的力学性能最好 ,微观组织具有等轴晶特点 ,拉伸断口具有韧窝断口特征 ;总结出熔化结合、部分熔化结合、机械结合三种结合方式 ,其中熔化结合力学性能和组织最好。

液锻金属物件的方法

本发明涉及用液锻制造金属物件的一种方法。液锻技术主要包括:将液态金属倒入模具,然后在压力下合模。这样,模具中的液态金属被合模动作所推动,使之充满模腔,同时不会裹进空气。金属在模具中一直保持受压状态,直至凝固。这样能保证所有可能形成的缩孔都会被充满压实。最后可开模,将物件从模具中取出。 众所周知,液锻可制出各种各样的物件,其材料以铝或铝合金为多。

新材料6063铝合金在液锻中的应用

一、前言液态模锻零件的材料大多是有色金属,通常用得较多的是铸铝类合金,如 ZL104、ZL201、ZL102等,锻铝类合金,如 LD_5、LD_(10)、LD_(11)等,超硬铝类合金,如 LC_4等。其它牌号的合金则很少应用或不适用。我们在开发自行车左、右曲柄(带五爪)和把立管等零件,大胆选用6063铝合金材料(相当于我国牌号 LD 类铝合金)。经两年来的努力,特别是经数百次反复探索。

空压机铝合金连杆直接液锻工艺探索

连杆是空压机能源转换中主要的受力零件,目前空压机普遍采用铝合金连杆。本文对空压机铝合金连杆直接液锻工艺进行探索,采用直接液锻的方式生产空压机铝合金连杆是可行的,其产品的性能可以完全的满足其使用的要求。工艺参数的选择是否合适,会直接影响液锻制件质量的好坏,在合适的温度和压力作用下能生产出力学性能较优、致密性能较好的液锻制件。

高温高压易溶型芯的研究

本文根据水溶材料和耐火材料的性质,研究了耐高温高压易溶型芯的材料配比及制造工艺,对浇注成型及压制成型所制得的易溶型芯性能进行了分析,确定了获得耐高温高压易溶型芯材料的最佳比例。

Influence of technical parameters on strength and ductility of AlSi9Cu3 alloys in squeeze casting

An orthogonal test was conducted to investigate the influence of technical parameters of squeeze casting on the strength and ductility of AISigCu3 alloys. The experimental results showed that when the forming pressure was higher than 65 MPa, the strength （ab） of A1Si9Cu3 alloys decreased with the forming pressure and pouring temperature increasing, whereas ab increased with the increase of filling velocity and mould preheating temperature. The ductility （6） by alloy was improved by increasing the forming pressure and filling velocity, but decreased with pouring temperature increasing. When the mould preheating temperature increased, the ductility increased first, and then decreased. Under the optimized parameters of pouring temperature 730 ℃, forming pressure 75 MPa, filling velocity 0.50 m/s, and mould preheating temperature 220 ℃, the tensile strength, elongation, and hardness of A1Si9Cu3 alloys obtained in squeeze casting were improved by 16.7%, 9.1%, and 10.1%, respectively, as compared with those of sand castings.

Homogenization on microstructure and mechanical properties of 2A50 aluminum alloy prepared by liquid forging

The homogenization on microstructure and mechanical properties of 2A50 aluminum alloy prepared by liquid forging was investigated.Wheel hubs were produced using direct and compound loading.The results show that the microstructure and mechanical properties are inhomogeneous in direct forged samples.The microstructure of the wall is coarser than that of the base,and the mechanical properties are lower and some defects are detected at the wheel corner.Using compound loading,the microstructure and mechanical properties of the wall are improved evidently.With increasing feeding amount,the microstructure and mechanical properties become more homogeneous.The defects disappear when the feeding amount is 4 mm.The forged wheel hubs could obtain fine and homogeneous microstructure with grain size of 20-30 μm,tensile strength of 355 MPa and elongation of 10% when the feeding amount is 10 mm.The microstructure and mechanical properties of liquid forged workpieces could be controlled and homogenized using compound loading.

铜基齿环毛坯管的半固态生产工艺及缺陷分析

介绍了应用半固态液锻方法生产铜基齿环毛坯管的工艺,结合连续铸造工艺、离心铸造工艺特点进行了对比分析.提出了克服产品缺陷的工艺措施：必须将模具预热温度控制在200～250 ℃,浇注温度取高于液相线温度50～100 ℃,控制好浇注速度,用复合精练剂对金属液精炼净化并及时去除液面浮渣等.结果表明,半固态液锻工艺具有设备结构简单合理、操作方便的特点,可以提高工艺出品率8%以上.

Forming properties and microstructure of Al-Cu alloy prepared by liquid-die forging

The Al-Cu wheel adopting the new Al alloy was prepared by the liquid-die forging,and the mechanical properties,composition distribution,microstructure and fracture behavior were investigated.The results showed that serious Cu segregation was found in the wheel specimen;the microstructure of the Al-Cu wheel was comprised of the casting microstructure and a small amount of the deformed microstructure;the best heat treatment and water quenching system were found to solution treated at(530±5)℃ for 4 h followed by(535±5)℃ for 24 h and aging treated at(155±5)℃ for 4 h;the fracture morphologies of the samples heated under T 6 and T 5-1 heat treatment showed flat,tough nest,and poor plastic characteristics;the fracture morphologies of the samples heated under T 4 heat treatment exhibited complete resilience,but no residual metallographic characteristic;the sample treated under T 4 protocol had the best elongation;the fracture failure was mainly due to the formation of the CuAl_(2)(θ)phases;and the fracture mechanism of the Al-Cu wheel was intergranular fracture.

Fabrication and performance analyses of 45#steel supports using liquid forging

In this paper,45#steel supports prepared by liquid forging showed excellent performances and the effects of processing techniques on the development of microstructures and mechanical properties of these steel supports were researched.The liquid forging process was simulated and technological parameters were optimized via a Pro CAST simulation software.The solidification time,temperature distribution,first principal stress distribution of the 45#steel supports varied with time,temperatures,and position.Two principal parameters,pouring temperature and dwell time,were assessed for their effects on microstructures,mechanical properties,and wear resistance properties of 45#steel supports.Results showed that the optimal pouring temperature of the molten metal and the pressure-holding time were between 1540℃ and 1560℃ and between 35 s and 40 s,respectively.The microstructure,mechanical properties,and fracture behavior of different positions in the support were also discussed,and the central position performed better than the edge because of plastic deformation.Finally,the dynamic solidification process was also investigated and the liquid forging process of 45#steel supports was complex and contained some special metal liquid convection and several plastic deformation stages.