Applications of Ni_3 (Si, Ti) Based Intermetallic Compounds to Chemical Parts, Heat Resistance and Wear Resistance Materials

1)具有上级耐蚀性和塑性的金属间化合物的发展（0.5-3at%），Ta（1-4at%）和硼（0.001-0.01wt%）显示出比Hastelloy D或Inconel 50中的那些具有上级耐硫酸性和良好延展性。2）显示出上级耐蠕变性的金属间化合物的开发Ti（7-11at%）-Si（5-12）-Co（1-30）合金沿着伪二元Ni_3（Si，Ti）-Co_3（Si，Ti）具有比Inconel 718更优异的蠕变强度。开发了可切削性和可抛光性，并且它们显示出适用于表壳或旋进部件。4）显示出超塑性的金属间化合物的开发Ni_3（Si，含硼和不含硼的钛合金在1073 - 1173 K温度范围内，应变速率低于5 × 10 ~（-3）/s时，均表现出超塑性变形<-4>。结果表明，该合金易于成形，并具有上级力学性能。5）放大及实际零件加工采用氧化铝坩埚感应炉在氩气保护下制备了大尺寸（&gt;2kg）铸锭，然后在高温力学试验机上加工成零件。6）组分与掺杂元素间的成键NMR测试表明，组分Ni与硼原子间存在强的定向键合。7）Ni_3（Si，Ti）合金特殊强度行为的系统观察通过对Ni_3Si和Ni_3（Si，Ti）合金中形变位错显微组织的透射电镜观察，解释了Ni_3Si和Ni_3（Si，Ti）合金中强度异常现象。

1) Development of intermetallic compounds showing superior corrosion resistance and ductilityIt was found that Ni_3 (Si, Ti) alloys with Cu (0.5-3at%), Ta (1-4at%) and boron (0.001-0.01wt%) showed superior sulfuric acid resistance and good ductility than those in Hastelloy D or Inconel 50.2) Development of intermetallic compounds showing superior creep resistanceIt was shown that Ni-Ti (7-11at%) -Si (5-12) -Co (1-30) alloys along pseudo-binary Ni_3 (Si, Ti) -Co_3 (Si, Ti) had more excellent creep strength than Inconel 718.3) Development of well-castable intermetallic compoundsWell-castable Ni_3 (Si, Ti) based intermetallic compounds with better corrosion resistance, machinability and polishability were developed and they were shown to be applicable to the watch case or the precession parts.4) Development of intermetallic compounds showing the superplasticityNi_3 (Si, Ti) alloys with and without boron were shown to display the superplastic deformation at 1073K-1173K at the strain rates below 5x10^<-4>/s. This result indicates that this alloy can be formed easily and the superior mechanical properties can be obtained.5) Scale up and working as actual partsLarge size ingots (>2kg) were made in Argon gas by the induction furnace using alumina crucible and then machined to the parts which were utilized as some parts in high temperature mechanical testing machine. Performance was reliable and excellent, and also the degradation was minimal.6) Interpretation of bonding between constituent and doping elementsStrongly directional bonding between constituent element Ni and boron atom were shown by NMR measurement. Also, the site of boron atoms was determined.7) Systematic observation for the peculiar strength behavior of Ni_3 (Si, Ti) alloysThe strength anomaly in Ni_3Si and Ni_3 (Si, Ti) alloys was interpreted based on the TEM observation for the deformed dislocation microstructures.