Xiaofeng Wei
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Xiaofeng Wei has a total of 5 co-authors. Here are the top co-authors by number of shared publications:
- Fu Wang
College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China
2 shared publications - Pengpeng Yan
College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China
2 shared publications - Xuewei Zhu
College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China
2 shared publications - Jian Peng
School of Materials Science and Engineering, Central South University, Changsha, People’s Republic of China
1 shared publication - Yuxiang Huang
College of Mechanical and Electronic Engineering, Northwest A&F University, Xianyang 712100, China
1 shared publication
Latest Publications
- Open Access
Interfacial Reaction and Microstructure Evolution of Sn-9Zn/Ni(Cu) Solder Joints
Sn-9Zn solder is a promising Pb-free solder, but it tends to form bulky intermetallic compounds (IMC) grains at the interface when soldered with common simple metal Cu or Ni substrates. Interfacial reaction between Sn-9Zn solder and Ni(Cu) solid solution substrates at 250 °C and 350 °C were systematically probed in this study. Results showed that when soldered at 250 °C, a Ni5Zn21 layer is formed at Sn-Zn/Ni-20Cu and Sn-Zn/Ni-40Cu joints; and Ni2Sn2Zn + Cu5Zn8 and Cu5Zn8 phases are formed in Sn-Zn/Ni-60Cu and Sn-Zn/Ni-80Cu joints, respectively. Fine-grained IMCs formed at the interface are formed even when the soldered time is prolonged to 16 h. This result indicates that Ni(Cu) solid solution substrates inhibit the rapid growth of IMC at the Sn-Zn/Ni-Cu interface. Ni(Cu) solid solution substrate can also provide various combinations of reaction products at the Sn-Zn/Ni-Cu joints. The Ni5Zn21 transfers to Ni2Sn2Zn + Cu5Zn8 phases when the Cu content increased to 60%, and a bi-layered structure Ni2Sn2Zn + Cu5Zn8 IMCs was formed in Sn-Zn/Ni(Cu) joints at 350 °C regardless of the Cu content in Ni(Cu) substrate (20–80%). These results would provide an effective support in designing Sn-Zn soldering system with optimized IMC layer to improve mechanical performance.
Open AccessInterfacial Reaction and Microstructure Evolution of Sn-9Zn/Ni(Cu) Solder Joints
Sn-9Zn solder is a promising Pb-free solder, but it tends to form bulky intermetallic compounds (IMC) grains at the interface when soldered with common simple metal Cu or Ni substrates. Interfacial reaction between Sn-9Zn solder and Ni(Cu) solid solution substrates at 250 °C and 350 °C were systematically probed in this study. Results showed that when soldered at 250 °C, a Ni5Zn21 layer is formed at Sn-Zn/Ni-20Cu and Sn-Zn/Ni-40Cu joints; and Ni2Sn2Zn + Cu5Zn8 and Cu5Zn8 phases are formed in Sn-Zn/Ni-60Cu and Sn-Zn/Ni-80Cu joints, respectively. Fine-grained IMCs formed at the interface are formed even when the soldered time is prolonged to 16 h. This result indicates that Ni(Cu) solid solution substrates inhibit the rapid growth of IMC at the Sn-Zn/Ni-Cu interface. Ni(Cu) solid solution substrate can also provide various combinations of reaction products at the Sn-Zn/Ni-Cu joints. The Ni5Zn21 transfers to Ni2Sn2Zn + Cu5Zn8 phases when the Cu content increased to 60%, and a bi-layered structure Ni2Sn2Zn + Cu5Zn8 IMCs was formed in Sn-Zn/Ni(Cu) joints at 350 °C regardless of the Cu content in Ni(Cu) substrate (20–80%). These results would provide an effective support in designing Sn-Zn soldering system with optimized IMC layer to improve mechanical performance.
- Open Access
High-Temperature Friction and Wear Properties of NiCr/hBN Self-Lubricating Composites
NiCr/hBN self-lubricating composites with hBN solid-lubricant contents of 8%, 9%, 10%, 11%, and 12% (mass fractions) were prepared by powder-metallurgy method. Their tribological properties at room temperature and 600, 700, and 800 °C were studied. SEM and XRD were performed to analyze their wear-surface morphology and abrasive-dust composition. Results indicate that the NiCr/hBN self-lubricating composites have favorable tribological properties at room temperature and 600 °C. The optimum comprehensive friction and wear performance are achieved at 10% hBN, and the main wear mechanism is abrasive wear. At 700 and 800 °C, the friction and wear properties of NiCr/hBN self-lubricating composites obviously decline. The wear surface experiences oxidation and the spinel oxides Cr2O3, NiCr2O4, and CrBO3 are formed. The main wear mechanism becomes combined scratching and glue form of adhesive wear, leading to greatly increased wear rate for the NiCr/hBN sel-lubricating composites.
Open AccessHigh-Temperature Friction and Wear Properties of NiCr/hBN Self-Lubricating Composites
NiCr/hBN self-lubricating composites with hBN solid-lubricant contents of 8%, 9%, 10%, 11%, and 12% (mass fractions) were prepared by powder-metallurgy method. Their tribological properties at room temperature and 600, 700, and 800 °C were studied. SEM and XRD were performed to analyze their wear-surface morphology and abrasive-dust composition. Results indicate that the NiCr/hBN self-lubricating composites have favorable tribological properties at room temperature and 600 °C. The optimum comprehensive friction and wear performance are achieved at 10% hBN, and the main wear mechanism is abrasive wear. At 700 and 800 °C, the friction and wear properties of NiCr/hBN self-lubricating composites obviously decline. The wear surface experiences oxidation and the spinel oxides Cr2O3, NiCr2O4, and CrBO3 are formed. The main wear mechanism becomes combined scratching and glue form of adhesive wear, leading to greatly increased wear rate for the NiCr/hBN sel-lubricating composites.