电渣熔铸模具钢/低合金钢双金属平板件组织与性能的研究

采用电渣熔铸方法制备Cr12MoV模具钢/40Cr结构钢双金属复合材料,研究了热处理工艺参数对双金属组织和性能的影响.结果表明:采用适当的熔铸工艺可获得界面结合牢固、均匀平整且过渡层适当的双金属平板件.双金属Cr12MoV钢一侧的淬火和回火组织为回火马氏体 网状共晶碳化物 细小粒状二次碳化物 少量残余奥氏体.双金属的最佳热处理工艺为980 ℃淬火 230 ℃回火,其冲击韧度αk值可达25 J/cm2以上,工作层硬度HRC≥62.     

电渣熔铸双金属复合材料界面的研究

采用电渣熔铸方法制备了Cr12MoV/20Cr双金属复合材料,研究了工艺参数对平板双金属界面结合状态及形状的影响.结果表明,在熔铸第一种合金后停留适当时间再熔铸第二种合金才能保证获得结合牢固且过渡层适量的平板双金属界面.增加电极数量或使电极与结晶器产生相对运动可避免双金属的U型界面、浇不足及冷隔等缺陷的产生.     

电渣熔铸双金属复合材料锤头的组织性能

用电渣熔铸的方法制造了双金属复合材料锤头。双金属复合锤头头部材料采用高铬铸铁,锤柄采用碳素结构钢。对复合材料锤头组织性能进行了测试和分析。结果表明,锤头和锤柄之间有一个复合层区域,两种材料间发生了熔融和相互渗透,实现了两种金属的有效冶金结合。装机试验结果表明,双金属复合锤头使用寿命是高锰钢锤头的2倍左右。     

电渣熔铸双金属复合锤头的研制

根据锤头的工况条件,提出了采用电渣熔铸制造双金属复合锤头的方法.双金属复合锤头头部材料采用高铬铸铁,锤柄采用碳素结构钢.所得到的双金属复合锤头结合界面为冶金结合.经过热处理后,金相组织为马氏体和弥散分布的硬度很高的M7C3型碳化物,锤头工作部位硬度(HRC)为56～58.装机试用结果表明,双金属复合锤头使用寿命是高锰钢锤头的2倍左右.     

电渣熔铸生产复合双金属材料的试验研究

用卧式电渣熔铸方法生产复合双金属材料，复合层厚度可以达到２０～３０ｍｍ。两种材料熔合处无裂纹、夹渣。电渣熔铸的复合层金属质量好，可满足不同工况需要。     

电渣熔铸双金属复合斗齿

根据对挖掘机斗齿的失效分析,提出了采用电渣熔铸钢铁复合斗齿的合理性和可能性.文中着重说明了电渣熔铸双金属斗齿的工艺,包括结晶器、自耗电极、渣系、电制度等的选择和设计.还就钢、铁接合部过渡区的性能和组织进行了分析.现场应用表明,电渣熔铸法生产的双金属复合斗齿的使用寿命比高锰钢斗齿提高3倍以上.     

电渣熔铸的发展

电渣熔铸的发展吴永正（贵州工学院贵州贵阳市：５５０００３）主题词：电渣熔铸，熔铸整体曲轴当前世界各工业发达国家的传统工业沿着高效率和大型化方向发展，同时加强高技术的开发和应用，加速制造工业的技术改造向高技术转化，并将现代尖端技术迅速转化为生产力。因此...     

电渣熔铸冷交换器顶盖

采用电渣技术试生产的冷交换器顶盖，组织致密、非金属夹杂物少，力学性能优于同类产品锻件，解决了顶盖产品锻件难于通过超声波探伤的难题。     

双金属异向对塑性变形的影响

在当前的各种器具中,双金属用的愈来愈多.本文对常用的双金属,在不同方向上取样,作单向拉伸试验,由异向系数ga=eb/ea,得出了在塑性变形过程中,不能忽略材料异向性的影响的结论.     

Effect of volume ratio of liquid to solid on the interfacial microstructure and mechanical properties of high chromium cast iron and medium carbon steel bimetal

The high chromium cast iron and medium carbon steel bimetal was fabricated by liquid-solid casting technology. The effect of volume ratios of liquid to solid (6:1, 10:1 and 12:1) on the interfacial microstructure and mechanical properties of bimetal was investigated. The interfacial microstructure was analyzed using scanning electron microscope (SEM) and transmission electron microscope (TEM). The shear strength and microhardness in as-cast condition were studied at room temperature. The results show that the volume ratios of liquid to solid affect significantly the interfacial microstructure. When liquid-solid volume ratio was 6:1, the unbonded region was detected in interface region because the imported heat energy cannot support effectively the diffusion of element, whereas, when liquid-solid volume ratios reach 10:1 and 12:1, a sound interfacial microstructure was achieved by the diffusion of C, Cr, Mo, Cu and Mn, and metallurgical bonding without unbonded region, void and hole, etc. was detected. With the increase of liquid-solid volume ratio, the elemental diffusion activity improves, resulting in the increase of width of interface transition region. At the same distance from interface, with the increase of liquid-solid volume ratio, the microhardness is degraded in HCCI, but increased in MCS. The shear strength is also improved with the increase of liquid-solid volume ratio.     

触变成形亚/过共晶铝-硅双金属复合材料性能研究

通过应变诱发熔化激活(SIMA)半固态触变模锻技术,制备了亚/过共晶铝-硅合金双金属复合铸造制品,其中亚共晶合金为Al-7Si合金,过共晶合金为Al-20Si合金。运用金相显微(OM)和电子扫描显微(SEM)技术对双金属复合材料界面组织和界面处的缺陷进行了分析;运用拉伸试验机对复合材料界面的结合性能进行了检测和分析。结果表明,界面处组织在压力的作用下相互融合均匀,界面处存在少量气孔、夹杂;室温拉伸试样都在过共晶Al-20Si合金一侧断裂,界面保持良好,其抗拉强度为113 N/mm2。经过计算,复合界面的结合强度大于80 N/mm2,该界面达到冶金结合。     

羟基磷灰石-氧化锆复合材料的致密化及其力学性能

在无压条件下,采用添加CaF2法制备了羟基磷灰石-氧化锆致密材料,并研究了CaF2含量对HA-ZrO2材料的致密化、微观结构和力学性能的影响.结果显示:在HA-ZrO2(10%～40%,质量分数,下同)复合材料中添加CaF2,使HA变成了分解温度高的氟部分取代羟基的磷灰石FHA,材料的密度和力学性能(抗弯强度和断裂韧性)明显提高;加入6%(质量分数)CaF2经1 350℃烧结4 h后,HA-ZrO2(10%～40%)的相对密度均达到95%,抗弯强度达到100～120 MPa,断裂韧性提高到1.2～1.6 MPa·m1/2;随ZrO2含量的升高,HA-ZrO2致密度有所下降;而当CaF2含量为6%,ZrO2含量高于40%时,HA-ZrO2复合材料中形成α-Ca3(PO4)2、HA/ZrO2固溶体或立方氧化锆,导致复合材料的力学性能下降.     

靶电流对非平衡磁控溅射制备无氢碳膜结构与性能的影响

利用非平衡磁控溅射(UBMS)技术在硅基片上制备了无氢碳膜,并采用Raman光谱、X射线衍射、傅立叶变换光谱等手段对不同靶电流下沉积的薄膜的微观结构、沉积速率、粗糙度、表面接触角及红外透过率进行了研究.试验结果表明:随着靶电流的增大,薄膜的沉积速率增大,薄膜中sp3键含量增加,薄膜表面接触角增大,红外透过率增大;而薄膜的粗糙度随靶电流增加而减小.靶电流是影响非平衡磁控溅射制备无氢碳膜结构与性能的1个主要因素.     

Microstructure and mechanical properties of 2D woven Grf/Al composite

A 2D woven graphite fibers reinforced aluminum matrix composite with 50%Grf （volume fraction） was fabricated by the squeeze-casting technology, and its microstructure and mechanical properties were investigated. The results show that the composite is dense, the graphite fibers are distributed uniformly in the composite. TEM observation indicates the bonding between fiber and matrix is good and little interfacial reaction is found in the Grf/Al composite. This is attributed to the better stability of graphite fiber and the fabrication process minimizing the contact time between fiber with matrix at high temperatures. The 2D woven Grf/Al composite exhibites better mechanical properties with tensile strength, bending strength and elastic modulus of 366.2, 519.7 and 110.7 GPa, respectively.＂ SEM images suggeste that the fracture is irregular and some pulled-out fibers are found, which indicats that the high strength of fiber is not degraded.     

Effect of extrusion on properties of Al-based composite

An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized conditions.The properties were characterized in terms of microstructure,hardness and sliding wear behaviour and then compared between the extruded and cast alloys and composites,in order to understand the benefits of composite and extrusion on the alloy.It was observed that composites drastically increased the hardness and the extruded composites further increased this value.The advantage of composites was realized in sliding wear tests.     

Mg对无压自浸渗制备SiCp/Al复合材料组织与性能的影响

采用无压自浸渗法制备SiCp/Al复合材料。研究了Mg含量对SiCp 与Al之间浸润性的影响 ;探讨了Mg含量对SiCp/Al复合材料的组织与性能的影响及其作用机理。结果表明 ,加入的Mg与SiCp 表面的氧化物薄膜和铝基体发生反应 ,生成物会阻止SiCp 与Al基体反应生成Al4 C3 脆性相 ,同时SiCp 表面的微反应也增加了基体与SiCp 的结合强度 ,改善了基体与SiCp 之间的浸润性 ,从而使复合材料的耐磨性提高了 3～ 4倍。