非晶Sm5Fe74.3Nb1.5Si11.7B4.5C2.5Cu0.5合金经预退火后的晶化动力学的DTA研究

研究了非晶Sm5Fe74.3Nb1.5Si11.7B4.5C2.5Cu0.5合金经400℃，保温10min预退火后的晶化动力学。结果表明；该合金的晶化相为α-Fe固溶体和Sm2Fe17Cx金属间化合物，两相的晶化表观激活能分别为557KJ/mol和514KJ/mol，当晶化体积分数为60%时，α-Fe相的晶化激活能达极大值；Sm2Fe17Cx相晶化激活能则随其晶化体积分数的增加而逐渐减小。     

Effect of Rare Earth Elements on Thermal Fatigue Property of Low Chromium Semi-Steel

The effect of rare earth elements on eutectic carbide‘s morphology of low chromium semi-steel in as-cast state and after heat treatment was investigated, and accordingly, the thermal fatigue property of this material was studied. The results show that RE can improve the eutectic carbide‘s morphology, inhibit the formation and propagation of thermal fatigue cracks, therefore, promote the thermal fatigue property, which is more noticeable in case of the RE modification in combination with heat treatment. The optimal thermal fatigue property can be obtained when treated with 0.2% RE modification as well as normalization at 950℃ for 3h.     

Effects of Zr on crystallization kinetics of Pr—Fe—B amorphous alloys

The effects of Zr on crystallization kinetics of Pr-Fe-B amorphous alloys have been investigated by DTA and XRD methods.It was found that for Pr8Fe86-xZrxB6(x=0,1,2)amorphous alloys,the final crystallized mixture is α-Fe and Pr2Fe14B,and the metastable Pr2Fe23B3 phase occurs during crystallization of Pr8Fe86B6 amorphous alloy,not during crystallization of Pr8Fe86-xZrxB6(x=1,2)amorphous alloys,By analyzing the activation energy of crystallization,the formation of an α-Fe/Pr2Fe14B composite microstructure with a coarse grain size in annealed Pr8Fe86B6 alloy,is attributed to a difficult nucleation and an easy growth for both the α-Fe and Pr2Fe14B in the alloy.The addition of Zr can be used to change the crystallization behavior of the α-Fe phase in Pr-Fe-B amorphous alloy,which is helpful to reduce the grain size for the α-Fe phase.     

深冷处理对TC6钛合金高温抗压能力的影响

采用热模拟试验机对深冷处理前后TC6钛合金进行热压缩实验,并结合显微组织、压缩断口观察和硬度测试,探讨了深冷处理对TC6钛合金高温抗压能力的影响。结果表明：深冷处理能提高TC6钛合金的高温抗压能力,在500 ℃条件下,深冷处理后TC6钛合金的抗压应力较深未经冷处理的提高了19.39%。     

高压高温处理对TC4钛合金微观力学性能的影响

通过对TC4钛合金进行高压高温处理,利用纳米压痕技术测试了高压高温处理前后TC4钛合金微观力学性能,借助光学显微镜和透射电镜对其组织进行分析,探讨了高压高温处理对TC4钛合金微观力学性能的影响。结果表明：高压高温处理能增大TC4钛合金的硬度、弹性模量和硬弹比,减小其蠕变速率,其原因主要是高压高温处理能细化TC4钛合金组织,增大合金内部的位错密度。     

LSI渗硼剂渗硼中硼的扩散激活能

通过对４０钢经不同温度及时间渗硼后渗层层深的测定,根据公式ρ＾２＝Ｋ０ｔｅ＾－Ｑ／ＲＴ计算出硼的扩散激活能,为渗硼层形成机制的研究提供数据。     

不同淬速下α-Fe/Nd2Fe14B复合纳米晶结构的形成

采用X射线衍射分析、透射电子显微分析技术及振动样品磁强计研究了ND3.6Pr5.4Fe83Co3B5合金熔体在不同淬速下α—Fe／Nd2Fe14B复合纳米晶结构的形成和磁性。结果表明．在淬速低于20m／s时随着淬速的升高Nd2Fe14B和α—Fe纳米晶的尺寸变得均匀、细小，α—Fe相的体积分数增加。当辊速由10m／s增加到20m／s时，Nd2Fe14B和α—Fe相的晶粒尺寸分别由51．2nm和30．2nm减小到13．4nm和16．3nm。α—Fe相的体积由31.9%增至48．6％，并在20m／s时获得了193．6kJ／m^3的最大磁能积。     

一种新的固体渗硼工艺

介绍一种廉价新型固体渗硼剂 ,并进行了渗硼工艺试验。结果表明 :采用该渗硼剂是可行的 ,可使钢件表面获得连续、均匀且无缺陷的渗硼层。     

40Cr钢传动轴断裂分析

应用化学分析,硬度检验及金相分析等方法对40Cr钢传动轴断裂原因进行了综合分析。结果表明：热加工温度对高是传动轴断理解的主要原因。同时提出了对40Cr钢传动轴验收的建议。     

热变形中铬白口铸铁性能的研究

对经４０％热变形后不同方式冷却的中铬白口铸铁的组织与性能进行观察与测试,并对其进行分析,所得结果对热变形中铬白口铸铁的应用具有重要的指导意义。