Henry Hu

Bio: Henry Hu is an academic researcher from University of Windsor. The author has contributed to research in topics: Magnesium alloy & Microstructure. The author has an hindex of 24, co-authored 130 publications receiving 2238 citations.

Mathematical modelling of solidification and melting: a review

Abstract: The major methods of mathematical modelling of solidification and melting problems are reviewed in this paper. Different analytical methods, nowadays still used as standard references to validate numerical models, are presented. Various mathematical formulations to numerically solve solidification and melting problems are categorized. Relative merits and disadvantages of each formulation are analysed. Recent advances in modelling solidification and melting problems associated with convective motion of liquid phase are discussed. Based on this comprehensive survey, basic guidelines are outlined to choose a correct mathematical formulation for solving solidification and melting problems.

Squeeze casting of magnesium alloys and their composites

Abstract: Squeeze casting, also known as liquid metal forging, extrusion casting and pressure crystallization, is a process in which molten metal soldifies in a die under an applied high pressure. The concept of squeeze casting was invented in Russia over 100 years ago. Later the process was exploited in North America, Japan and Europe to produce various automotive components. With the rapid expansion of magnesium applications in the automotive industry, the development of squeeze casting technology for magnesium alloys and their composites has been motivated by incentives to produce high-quality components. The present paper reviews recent progress in squeeze casting, and the effects of process variables on the cast structure and properties of magnesium alloys and magnesium-based composites. Approaches to optimization of the squeeze-casting process are discussed. The significant advantages of squeeze-cast magnesium alloys and magnesium-based composites are highlighted. The on-going research work at ITM is presented.

Potential Magnesium Alloys for High Temperature Die Cast Automotive Applications: A Review

Abstract: Magnesium, as a lightweight construction material, has rapidly grown its applications in the automotive industry since the early 1990s. To maximize the weight reduction of vehicles by lightweight magnesium alloys in the coming years, the use of newly developed high-temperature magnesium alloys is expected to increase significantly, particularly in the powertrain applications where the creep resistance is always required. This article reviews recent developments of the creep-resistant magnesium alloys. Fundamental aspects of the creep deformation theory and mechanisms are described. The metallurgical principles for designing the creep-resistant alloys are highlighted. The creep behavior of magnesium and its conventional alloys is discussed based on some microstructure analyses. The mechanical properties, microstructure, and manufacturability of the newly developed creep-resistant magnesium alloys are also overviewed. The further research and development work is outlined in terms of developing magn...

Mechanical and tribological properties of self-lubricating metal matrix nanocomposites reinforced by carbon nanotubes (CNTs) and graphene – A review

Abstract: Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix nanocomposites for structural engineering and functional devices. Carbonous materials, such as graphite, carbon nanotubes (CNT's), and graphene possess unique electrical, mechanical, and thermal properties. Owe to their lubricious nature, these carbonous materials have attracted researchers to synthesize lightweight self-lubricating metal matrix nanocomposites with superior mechanical and tribological properties for several applications in automotive and aerospace industries. This review focuses on the recent development in mechanical and tribological behavior of self-lubricating metallic nanocomposites reinforced by carbonous nanomaterials such as CNT and graphene. The review includes development of self-lubricating nanocomposites, related issues in their processing, their characterization, and investigation of their tribological behavior. The results reveal that adding CNT and graphene to metals decreases both coefficient of friction and wear rate as well as increases the tensile strength. The mechanisms involved for the improved mechanical and tribological behavior is discussed.

Spectroscopic study of electrolytic plasma and discharging behaviour during the plasma electrolytic oxidation (PEO) process

Abstract: In this study, a plasma electrolytic oxidation (PEO) process was used to produce oxide coatings on commercially pure aluminium (1100 alloy) at a pulsed dc power mode. The effects of process parameters (i.e. current density and treatment time) on the plasma discharge behaviour during the PEO treatment were investigated using optical emission spectroscopy (OES) in the visible and near ultraviolet (NUV) band (285–800 nm). The elements present in the plasma were identified. Stark shifts of spectral lines and line intensity ratios were utilized to determine the plasma electron concentrations and temperatures, respectively. The plasma electron temperature profile, coating surface morphology and coating composition were used to interpret the plasma discharging behaviour. The different coating morphologies and compositions at different coating surface regions are explained in terms of three types of discharge, which originate either at the substrate/coating interface, within the upper layer, or at the coating top layer. The high spike peaks on the plasma intensity and temperature profiles corresponded to discharges originated from the substrate/coating interface, while the base line and small fluctuations were due to discharges at the coating/electrolyte interface.