陈体军
,
郝远
,
孙军
,
狄杰建
中国有色金属学报
用SEM和TEM对金属型铸造并经18个月自然时效的Z A27合金的微观组织进行了观察. 结果表明: ZA27合金凝固的初生相为富Al的树枝状α′相, 随后在α′相周围形成一层富 Zn的包晶β相 , 最后剩余液体发生共晶反应, 共晶β优先依附于包晶β相形核、长大, 而共晶η则在包晶β相间形成一层薄膜, 在有些区域则形成棒状共晶组织; 在随后的冷却及时效过程中 , β发生胞状分解形成规则的共析α+η层片组织或不规则的复杂形状组织, 共析胞以共晶η相为基形核, 并向枝晶中心生长, 使α′相也分解为层片α+η组织, 当其生长被α′中心的连续分解所阻挡时, 致使其芯部形成细小的α+η颗粒组织; 富Cu的ε相存在于所有η相中.
关键词:
ZA27合金
,
金属型铸造
,
自然时效
,
微观组织
徐维普
,
刘秀忠
材料导报
分析了高强度ZA合金的焊接性能,在大量试验的基础上,研制出了一种新型的适合高强度ZA合金钎焊的钎料CZ5#.该钎料具有熔点低,对母材的润湿性好,钎焊接头组织中含有强度、硬度较高的呈弥散分布的固溶体,以及接头强度较高等特点.
关键词:
ZA合金
,
钎料
,
钎焊接头
J.C. Wang
,
Z.M. Zhang
,
Y.L. Lu
,
G.S. Song and G.C. Yang (State Key Laboratory of Solidification Processing
,
Northwestern Polytechnical University
,
Xi'an 710072
,
China)
金属学报(英文版)
To improve the damping capacities of metals and alloys, the microstructures and damping capacities of ZA27 alloy modified by Zr were studied, and the damping capacities at room tempemture were measured by using cantilever beam techniques. The experiment results show that Zr can refine the Al-rich primary phase and improve the damping Capacities saliently. Compared with the un-modified one, the damping capacity of ZA27 alloy modified by 0.3wt%Zr received 90 percent increment. The high damping capacities are attributed primarily to grain ablement and the increasing of phase interfaces.
关键词:
ZA27 alloy
,
null
,
null
,
null
null
,
null
,
null
,
null
金属学报(英文版)
ZA27 alloy was prepared by casting with permanent mold and then annealed at 250℃ for 1-4h. The damping capacity of the alloy was measured using a testing apparatus based on the cantilever beam technique. It was found that the as-cast ZA27 alloy possesses high damping capacity with the value of 1.3 × 10-3 at 320Hz. After annealed at 250℃ for 1h, the damping capacity decreases to 1.1 × 10-3 and then remains constant even when the annealing time is increased to 4h. The microstructure of the as-cast ZA27 alloy consists of large dendrites of Al-rich primary α-phases, eutectoid (α + η) and nonequilibrium eutectic phases (α + η + ε). After annealing at 250℃ for 1h, the ε phase disappears due to dissolution into the matrix, and the spacing between the flakes of eutectoid increases. The further increase in the annealing time has little effect on the spacing. The damping mechanism of the alloy was discussed considering the thermoelastic damping and defect damping. The value of thermoelastic damping accounts only for 7%-8% in the overall damping in cantilever beam damping measurements and the damping capacity of the ZA27 alloy came mainly from defect damping.
关键词:
damping capacity
,
null
,
null
谭银元
,
严汉芳
中国有色金属学报
研究了稀土对ZA27合金力学性能和组成相的分布、形状及数量的影响. 结果表明, 稀土能细化晶粒, 提高力学性能, 使树枝状的α相变成杆状分布, ε相呈弥散分布, α相数量变少, ε+η相数量增多.
关键词:
稀土
,
ZA27合金
,
力学性能
,
相
李合琴
,
何晓雄
,
董旭
材料热处理学报
通过对锌铝合金ZA27进行365℃固溶和250℃人工时效,在0.1、0.3、1.0Hz 3个振动频率下,测试了铸态和固溶时效态合金从室温到400%的阻尼随温度、频率、应变振幅的变化规律,研究了阻尼行为与相应微观组织之间的关系.根据AL-Zn二元合金平衡相图,分析了ZA27合金在平衡和实际冷速下所结晶的铸态和固溶时效组织.结果表明:铸态ZA27合金阻尼的大小与频率有关、与应变振幅无关;在300℃附近阻尼一温度曲线出现的阻尼峰位不随频率的改变而移动,说明在此温度有一级固态相变;经固溶时效后,合金组织明显细化,阻尼特性基本不变,但阻尼峰值明显高于铸态合金,表明固溶时效不改变ZA27合金的阻尼特性,但显著提高了合金的阻尼.
关键词:
锌铝合金ZA27
,
固溶
,
时效
,
低频阻尼
,
显微组织
刘敬福
,
陈鹏飞
,
李荣德
表面技术
doi:10.3969/j.issn.1001-3660.2009.05.002
为了对合金元素Mn如何影响ZA35合金的电化学腐蚀性能有更深的认识,采用动电位极化方法测试了铸态ZA35和1.0%Mn-ZA35合金在不同温度的NaCl水溶液中的开路电位和极化曲线,分析了温度和合金元素Mn对合金电化学腐蚀性能的影响.实验结果显示:随着NaCl溶液温度升高,合金的开路电位下降(负移),并且1.0%Mn-ZA35合金较铸态ZA35的开路电位低;NaCl溶液温度升高,铸态ZA35合金和1.0%Mn-ZA35合金腐蚀电流密度逐渐增加;相同温度下,1.0%Mn-ZA35合金较铸态ZA35合金腐蚀电流密度大.Mn做为合金元素,在ZA35合金基体中固溶度很小,1.0%Mn-ZA35合金中析出富锰相,降低了耐腐蚀性能.
关键词:
ZA35合金
,
NaCl水溶液
,
温度
,
极化曲线
,
富锰相
