材料期刊网

Joining of Zirconia and Ti-6Al-4V Using a Ti-based Amorphous Filler

Yuhua Liu

材料科学技术（英）

Polycrystalline ZrO₂-3 mol.%Y₂O₃ was brazed to Ti-6Al-4V by using a Ti₄₇Zr₂₈Cu₁₄Ni₁₁(at.%) amorphous ribbon at 1123-1273 K in a high vacuum. The influences of brazing temperature on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be described as ZrO₂/TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O/α-Ti+(Ti,Zr)₂(Cu,Ni) eutectic/acicular WidmanstÄaten structure/Ti-6Al-4V alloy. With the increase in the brazing temperature, the thickness of the TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O layer reduced, the content of the α-Ti+(Ti,Zr)2(Cu,Ni) eutectic phase decreased, while that of the coarse α-Ti phase gradually increased. The shear strength of the joints did not show a close relationship with the thickness of the  TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O layer. However, when the coarse (Ti,Zr)₂(Cu,Ni) phase was non-uniformly distributed in the α-Ti phase, or when α-Ti solely situated at the center of the joint, forming a coarse block or even connecting into a continuous strip, the shear strength greatly decreased.

关键词: Brazing

Effect of parameters on interface of the brazed ZrO₂ ceramic and Ti-6Al-4V joint using Ti-based amorphous filler

Yuhua LIU

金属学报(英文版)

A commercially available Ti₄₇Zr₂₈Cu₁₄Ni₁₁ (at. pct) amorphous filler foil was used to join ZrO₂ ceramic and Ti-6Al-4V alloy. According to experimental observations, the interface microstructure accounts for the mechanical properties of the joints. The effects of brazing conditions and parameters on the joint properties were investigated. The joint shear strength showed the highest value of about 108 MPa and did not monotonously increase with the brazing time increasing. It was shown that decreasing of brazing cooling rate and appropriate filler foil thickness gave higher joint strength.

关键词: Brazing

Joining of Zirconia and Ti-6Al-4V Using a Ti-based Amorphous Filler

Yuhua Liu

材料科学技术（英）

Polycrystalline ZrO₂-3 mol.%Y₂O₃ was brazed to Ti-6Al-4V by using a Ti₄₇Zr₂₈Cu₁₄Ni₁₁(at.%) amorphous ribbon at 1123-1273 K in a high vacuum. The influences of brazing temperature on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be described as ZrO₂/TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O/α-Ti+(Ti,Zr)₂(Cu,Ni) eutectic/acicular WidmanstÄaten structure/Ti-6Al-4V alloy. With the increase in the brazing temperature, the thickness of the TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O layer reduced, the content of the α-Ti+(Ti,Zr)2(Cu,Ni) eutectic phase decreased, while that of the coarse α-Ti phase gradually increased. The shear strength of the joints did not show a close relationship with the thickness of the  TiO+TiO₂+Cu₂Ti₄O+Ni₂Ti₄O layer. However, when the coarse (Ti,Zr)₂(Cu,Ni) phase was non-uniformly distributed in the α-Ti phase, or when α-Ti solely situated at the center of the joint, forming a coarse block or even connecting into a continuous strip, the shear strength greatly decreased.

关键词: Brazing

不锈钢板翅结构蠕变的有限元分析

蒋文春 , 巩建鸣 , 陈虎 , 涂善东

金属学报

基于有限元软件ABAQUS，利用Norton蠕变本构关系，根据铸态镍基钎料BNi-2和0Cr18Ni9不锈钢母材的蠕变材料参数，对采用钎焊结构的微型不锈钢板翅式换热器进行整体600℃下的蠕变变形有限元分析，得到10万小时后的蠕变变形分布规律，预测到板翅式换热器在高温下的变形和危险位置。结果表明，由于钎料和母材力学性能参数的不匹配，钎焊过程中在接头处产生了较大的残余应力，对钎焊接头的蠕变变形产生较大影响。在钎角处，蠕变应变和应力较大，且分布不均匀，界面应力应变分布呈不连续和不协调特性，对蠕变失效的影响较大。

关键词: 板翅结构 , Brazing , Residual Stress

Effects of Al2O3 Particulates on the Thickness of Reaction Layer of Al2O3 Joints Brazed with Al2O3-Particulate-Contained Composite Filler Materials

Jianguo YANG , Jingwei WU , Hongyuan FANG

材料科学技术（英）

In order to understand the rate-controlling process for the interfacial layer growth of brazing joints brazed with active composite filler materials, the thickness of brazing joints brazed with conventional active filler metal and active composite filler materials with different volume fraction of A2O3 particulate was studied. The experimental results indicate although there are A2O3 particulates added into active filler metals, the time dependence of interfacial layer growth is t2 as described by Fickian law for the joints brazed with conventional active filler metal. It also shows that the key factor affecting the interfacial layer growth is the volume fraction of alumina in the composite filler material compared with the titanium weight fraction in the filler material.

关键词: Composite filler material , null , null , null

Effect of Filler Composition on the Brazing of Alumina to Copper Using Ultrasonic Wave

Khalid M.HAFEZ , Masaaki NAKA

材料科学技术（英）

An ultrasonic wave was applied during brazing of alumina to Cu. First alumina was metallized by applying ultrasonic wave in braze bath. Then the metallized alumina was brazed with Cu using the same filler alloy. The filler used were Zn-Al alloys and Zn-Sn Alloys. The weight percent of Al in filler was ranging between 0, 5%, 10%, respectively. The weight percent of tin in filler was ranging between 0, 30%, 60% and 91%, respectively. The joining mechanism was investigated by measuring the joining strength, hardness and analyzing the microstructure at interface of the joint. The shear strength and microstructure of the joint strongly depend on the filler composition. The effect of ultrasound was derived primarily from acoustic cavitations, impact and friction of the filler against alumina ceramic. This improved the wetting between alumina and the filler, and reflected to improve the joint strength. Another ultrasonic advantage as to reduce of the joining temperature, that reduced the thermal stress in the braze joint.

关键词: Alumina , null , null , null , null , null

Numerical Simulation of Brazing TiC Cermet to Iron with TiZrNiCu Filler Metal

Lixia ZHANG , Jicai FENG

材料科学技术（英）

The maximum thermal stress and stress concentration zones of iron/TiC cermet joint during cooling were studied in this paper. The results showed that the shear stress on iron/TiC cermet joint concentrates on the interface tip and the maximum shear stress appears on the left tip of iron/TiZrNiCu interface. Positive tensile stress on TiC cermet undersurface concentrates on both sides of TiC cermet and its value decreases during cooling. Negative tensile stress on TiC cermet undersurface concentrates on the center of TiC cermet and its value increases during cooling. Brazing temperature has little effect on the development and maximum thermal stress.

关键词: Numerical simulation , null , null , null

Joining of Zirconia and Ti-6Al-4V Using a Ti-based Amorphous Filler

材料科学技术（英）

关键词: 非晶薄带 , 氧化锆 , 钛基 , Ti , 界面微结构 , 二氧化钛 , 填料 , 钎焊温度

Effect of parameters on interface of the brazed ZrO2 ceramic and Ti-6Al-4V joint using Ti-based amorphous filler

金属学报(英文版)

关键词:

Sr,Ti对Al-Si-Zn钎料6061铝合金钎焊接头组织的影响

戴玮 , 薛松柏 , 孙波 , 娄江 , 王水庆

稀有金属材料与工程

制备了Sr及Ti变质的Al-Si-Zn钎料,并将其应用于6061铝合金的钎焊,研究Sr及Ti对Al-Si-Zn钎制6061铝合金钎焊性能的影响.结果表明:锌的加入使得钎料熔点由铝硅共晶温度下降至520℃左右.添加少量改性元素Sr及细化晶粒元素Ti,极大优化了钎料中Al-Si共晶的形态与分布,同时也细化了钎料中的α-Al固溶体.向钎料中添加0.08％Ti元素,使得原来Al-Si-Zn-Sr-0.04Ti钎料钎缝中大块团簇状的铝硅共晶均匀分布于α-Al固溶体之间.在6061铝合金钎的焊界面处可以发现较为明显的过渡层,由于钎焊过程中母材元素发生了向钎料中扩散,母材中的锰元素与钎料中的铁杂质生成块状锰铁相避免了针状β-Fe的生成.

关键词: 钎焊 , 6061铝合金 , Al-Si-Zn钎料 , Ti