A Preliminary Study of Fabrication Technology for Dynamic Compression Plates Using Centrifugal Casting Process

The high cost of health services in low-income countries has caused them to produce implants and medical devices at low cost. This research highlights a preliminary study of the design concept, mould design, and fabrication of horizontal type centrifugal casting machines for the manufacture of dynamic compression plates materials. Normally, dynamic compression plate is produced from materials such as 316L stainless steel, cobalt, and titanium alloys. In this work, aluminium-silicon alloy was used in this preliminary study. Aluminium-silicon alloy was melted at a temperature of 730 °C and poured into a mould with a rotational speed of 1500 rpm. Tensile, hardness and microstructure investigation were carried out to discern the mechanical properties of the cast product from the horizontal type centrifugal casting machine. Results showed the measured value of tensile strength is not significantly different in the two zones of cast pipe, the butt zone of fall of molten metal (specimen A) was 147 MPa, and the butt-end zone (specimen B) was 142 MPa. The hardness value for the as-cast pipe obtained from the outside, middle, and inside, was 104.0, 92.9, and 80.3 HV, respectively. Evaluation of microporosity in fractures (from tensile test) results from horizontal type centrifugal castings showed a small distribution. Meanwhile, the calculation of the contour hole processing time for DCP with eight holes is 38 minutes per implant.

Numerical Simulation of Solidification of Thick-Wall Stainless Steel Pipe in Horizontal Centrifugal Casting Process

A mathematical model of the horizontal centrifugal casting process based on the cast cylindrical coordinates for stainless steel pipe has been developed. Thermal boundary conditions, including the radiative and convective heat transfer conditions, have been taken into consideration. The model equation was solved numerically using non-uniform cylindrical grids and the finite differential method (FDM). Several parameters of casting process such as melt superheat, preheating temperature of mold, thermal conductivity of coating and flux powder, which affect the temperature distributions in both cast pipe and mold and the changed positions of melt solidifying at last are investigated. In order to verify the results of simulation, calculated temperatures were compared with the experimental data.

Study on the Amount of SiO2 on the Thermal Resistance of the Ceramic-Lined Composite Cast Iron Pipe

The amount of SiO2on the thermal resistance of the ceramic lined cast pipe fabricated by self-propagating high temperature synthesis technology was investigated. Results indicated that the ceramic-lined composite cast iron pipe had excellent thermal resistance. With the increase of the additive SiO2amount, the thicknesses and cavity of the ceramic liner increased, which led to the increase in their thermal resistance. In a given ceramic-lined composite cast iron pipe, its thermal resistance increased with the increase of the center temperature.