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通过测量粉末烧结Nd15F377B8永磁合金的充磁和退磁曲线,结合金相组织及磁畴观察分析,证明该合金的矫顽力是由畴壁的钉扎来控制。 相似文献
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《中国航空学报》2021,34(4):375-386
Laser welding of dissimilar titanium/aluminum alloys has been employed at an increasing rate, particularly in the aerospace industry, owing to its advantages in terms of current design flexibility and fuel/cost savings. The major problem with dissimilar Ti/Al welds arises from the difference in the thermal expansion and contraction of the two metals, which leads to hot-cracking susceptibility and the mitigation of the mechanical property after welding. In the present study, pulsed Nd:YAG laser welding of Ti6Al4V and AA6060 has been addressed. Hot-cracking susceptibility in the heat affected zone and the shear fracture behavior of the lap joints were investigated through microstructural characterization and mechanical tests. The results indicate that the hot cracking tendency can be reduced by increasing the pulse peak power (7.5–8.5 kW) and the laser point diameter (0.8–1.0 mm) with specific pulse duration and overlap. An alternative control strategy for less hot cracks in the Ti/Al lap joint can be to increase the weld width and decrease the cooling rate during solidification. The shear fracture of the Ti/Al lap joint is likely to occur along the lower side path of the weld interface with decreasing weld surface collapsed amount and increasing aluminum base metal melt depth. 相似文献
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ICP-AES法测定钛基复合材料中的Sn, Zr, Nb, Ta, Nd和Fe的研究 总被引:2,自引:0,他引:2
采用ICP-AES法对钛基复合材料中的合金元素Sn,Zr,Nb,Ta,Nd,Fe的测定进行了研究,着重进行了基体元素及待测元素Sn,Zr,Nb,Ta,Nd,Fe之间干扰试验及各元素在测定浓度范围内的线性相关性试验,进行了酸度试验及Ta,Nb,Zr的酸不溶试验,测定了钛基复合材料中上述六元素的含量,得到了较好的精密度和准确度.方法简便可靠,可获得满意的分析结果. 相似文献
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Institute for Laser Physics V.A.Serebryakov K.V.Gratzianov A.S.Eremenko A.A.Timopheev SPBSUITMO M.V.Volkov 《航空制造技术》2006,(1):69-72
The first experiments on hardening metals by laserpeening induced residual compressive stress in the sur-face of metals for improving their resistance to cracking,stress corrosion and fatigue took place more than 30years ago. However, only today, with the development ofhigh-intensity pulse repetitive rate lasers, this methodstarts to compete to traditional peening, which use influ-ence of small metal balls.Laser peening uses pulses with high intensity 109 ̄1010 W/cm2 [1]. The laser energy abso… 相似文献
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