Sen YANG
,
Wenjin LIU
,
Minlin ZHONG
,
null
,
null
材料科学技术（英）
A Ni-base alloy composite coating reinforced with TiC particles of various shapes and sizes on medium carbon steel substrate was produced by multilayer laser cladding. The chemical compositions, microstructures and surface morphology of the cladded layer were analyzed using energy dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM), and X-ray diffractometry (XRD). The experimental results showed that an excellent metallurgical bonding between the coating and the substrate was obtained. The microstructure of the coating was mainly composed of γ-Ni dendrites, a small amount of CrB, Ni3B, M23C6 and dispersed TiC particles. Much more and larger TiC particles formed in the overlapping zone, which led to a slightly higher microhardness of this zone. The maximum microhardness of the coating was about HV0.21200. The effects of the laser processing parameters on the microstructures and properties of coating were also investigated.
关键词:
Laser cladding
,
null
,
null
,
null
Mingzhen MA
,
Dayong CAI
,
Tianhua WEI
材料科学技术（英）
Direct reaction synthesis (DRS), based on the principle of self-propagating high-temperature synthesis (SHS), is a new method for preparing particulate metal matrix composites. TiCP/Al-4.5Cu-0.8Mg composites were fabricated by DRS. Particulate composites were fabricated with Ti carbide (TiC) particles, generally less than 1.0µm. The reacted, thermal extruded samples exhibit a homogeneous distribution of fine TiC particles in Al-4.5Cu-0.8Mg matrix. Mechanical property evaluation of the composites has revealed a very high tensile strength relative to the matrix alloy. Fractographic analysis indicates ductile failure.
关键词:
TiCP/Al-4.5Cu-0.8Mg composites
,
null
,
null
,
null
杨志强
,
刘勇
,
田保红
,
张毅
材料热处理学报
利用Gleeble-1500热力模拟试验机,获得了20 vol％ TiC颗粒增强弥散铜基复合材料在温度为450 ～850℃、应变速率为0.001 ～1 s-1的真应力-应变数据.采用加工硬化率处理方法,研究了该复合材料的动态再结晶行为.结果表明,该材料的真应力-应变曲线主要以动态再结晶软化机制为特征,峰值应力随变形温度的降低或应变速率的升高而增加;该材料的lnθ-ε曲线出现拐点,-(a)(lnθ)/(a)ε-ε曲线均出现极小值;峰值应变和临界应变均随变形温度的升高与应变速率的降低而减小;临界应变与峰值应变之间具有相关性,即εc／εp=0.5276.
关键词:
TiC颗粒
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弥散铜
,
动态再结晶
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临界条件
丁兰英
,
傅玉灿
,
陈燕
,
苏宏华
,
向孙祖
,
徐九华
,
徐鸿钧
人工晶体学报
在Ag-Cu-Ti合金中加入一定量的TiC颗粒制成复合钎料,进行细粒度金刚石磨粒与45钢基体的真空钎焊实验.运用三维视频显微镜、扫描电镜和X射线衍射仪分析TiC颗粒、Ag-Cu-Ti合金和金刚石磨粒之间的结合界面.结果表明:TiC颗粒能有效降低试验工艺下Ag-Cu-Ti合金在基体表面的流动性和结晶时产生的隆起,复合钎料在基体表面分布更趋平整,有利于细粒度金刚石钎焊等高性的控制；适量TiC颗粒在结合剂层中的均匀分布,能显著细化结合剂层的显微组织；复合钎料中添加TiC颗粒在实现细粒度金刚石磨粒与钢基体钎焊连接的同时,有效抑制了钎料合金对细粒度金刚石磨粒过度浸润所造成切削刃的包裹,保证了细粒度金刚石磨粒良好的出露.
关键词:
TiC颗粒
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细粒度金刚石磨粒
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Ag-Cu-Ti合金
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界面
孟君晟
,
史晓萍
,
王振廷
,
王永东
,
胡海亭
材料热处理学报
以Al粉、Ti粉和C粉为原料,利用氩弧熔敷技术,在ZL104合金表面原位合成了TiC增强Al基复合材料层,借助扫描电镜、X射线衍射仪对复合涂层的组织进行了分析;利用显微硬度计、摩擦磨损试验机对复合涂层性能进行了测试。结果表明,氩弧熔敷过程中可以充分反应合成TiC颗粒;TiC颗粒呈球状分布,颗粒尺寸约为1.5μm,均弥散分布于熔敷层中。熔敷层与基体呈冶金结合,无裂纹、气孔等缺陷;复合涂层的显微硬度可达660 HV0.2,涂层耐磨性较基体提高近7倍。
关键词:
氩弧熔覆
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原位合成
,
TiC颗粒
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显微组织
,
耐磨性
孟君晟
,
王振廷
,
史晓萍
,
徐家文
材料热处理学报
利用氩弧熔敷技术在16Mn钢表面原位合成TiC增强Ni基复合材料耐磨涂层.采用XRD、SEM等手段分析涂层的组织,测试涂层的室温干滑动磨损性能.结果表明:其室温干滑动磨损机制为显微切削磨损,熔敷层与基体呈冶金结合,TiC颗粒均弥散分布于熔敷层中.涂层有较高的硬度,在室温干滑动磨损试验条件下具有优异的耐磨性.
关键词:
氩弧熔敷
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原位自生
,
TiC颗粒
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摩擦磨损
龚建勋
,
许继青
,
路德斌
,
吴慧剑
机械工程材料
用埋弧焊制备铁-碳-铬-硅合金堆焊层,通过显微组织观察、硬度测试和耐磨性能试验等方法研究了外加TiC颗粒含量对其显微组织及耐磨性的影响.结果表明:不同TiC含量的铁-碳-铬-硅合金堆焊层基体组织均为α-Fe,随TiC含量增加,初生M7C3颗粒尺寸从40～80μm逐渐减小至15～25 μm,颗粒数量增多,分布弥散,且出现了TiC2和TiC等增强相;弥散密集分布的M7 C3颗粒有利于堆焊合金层表面均匀磨损,避免因粗大脆性共晶优先磨损引起的过早失效,显著改善了耐磨性;该合金堆焊层的耐磨性随TiC含量的增加先增强,接着减弱,然后再增强,其主要磨损机理由微观断裂转变为微切削.
关键词:
堆焊
,
显微组织
,
耐磨性
,
TiC颗粒
,
合金层
