Dewaxing of ABS rapid prototype pattern for ceramic invesment casting of proximal humerus

Orthopedic implants can be defined as medical devices used to replace or provide fixation of bone or to replace articulating surfaces of a joint. Many proximal humerus bone cases require almost immediate/short lead time surgery. Thus rapid respond from the manufacture is very crucial. The manufacture of surgical implant often requires the use of machining process. Current trend shows that preform either from casting or forging is preferred to reduce machining cost and time. It is expected that by employing rapid manufacture using rapid prototyping and investment casting process could expedite the manufacturer to surgery time. The objective of this project is to evaluate the effect of dewaxing time on collapsibility characteristic of solid and hollow constructed rapid prototyped proximal humerus ABS pattern.FDM2000 machine was used to build the ABS patterns. Acrylonitrile Butadiene Styrene (ABS) P400 was used for pattern material in this study. Output responses investigated were collapsibility, expansion defects. ABS hollow and solid pattern are prepared and are subjected to dewaxing in different time and temperature. The ABS hollow and solid pattern were compared based on the dewaxing process results, ceramic shell defects. The best pattern material according to the optimum time and temperature was chosen based on the results and compared with the reference process. This study is expected to assist the investment caster to estimate the decomposition temperature and allowance required in preparing a mould from ABS pattern as well as in the initial CAD drawings to produce a final casting with minimal dimensional in accuracy. It is hoped that the outcome of this study will assist the casting industries especially in biomedical in using the advanced product support tools using CAD and RP technology for higher productivity and quality products

Dewaxing of ABS rapid prototype pattern for ceramic investment casting of proximal humerus

Orthopedic implants can be defined as medical devices used to replace or provide fixation of bone or to replace articulating surfaces of a joint. Many proximal humerus bone cases require almost immediate/short lead time surgery. Thus rapid respond from the manufacture is very crucial. The manufacture of surgical implant often requires the use of machining process. Current trend shows that preform either from casting or forging is preferred to reduce machining cost and time. It is expected that by employing rapid manufacture using rapid prototyping and investment casting process could expedite the manufacturer to surgery time. The objective of this project is to evaluate the effect of dewaxing time on collapsibility characteristic of solid and hollow constructed rapid prototyped proximal humerus ABS pattern.FDM2000 machine was used to build the ABS patterns. Acrylonitrile Butadiene Styrene (ABS) P400 was used for pattern material in this study. Output responses investigated were collapsibility, expansion defects. ABS hollow and solid pattern are prepared and are subjected to dewaxing in different time and temperature. The ABS hollow and solid pattern were compared based on the dewaxing process results, ceramic shell defects. The best pattern material according to the optimum time and temperature was chosen based on the results and compared with the reference process. This study is expected to assist the investment caster to estimate the decomposition temperature and allowance required in preparing a mould from ABS pattern as well as in the initial CAD drawings to produce a final casting with minimal dimensional in accuracy. It is hoped that the outcome of this study will assist the casting industries especially in biomedical in using the advanced product support tools using CAD and RP technology for higher productivity and quality products

Optimization of Electrical Discharge Machining Parameters of Co-Cr-Mo Using Central Composite Design

The optimization of electrical discharge machining (EDM) parameters of Cobalt Chromium Molybdenum (Co-Cr-Mo) is performed using central composite design to improve the process efficiency in terms of increasing material removal rate and electrode utilization time. The effects of pulse on time, pulse off time, voltage and current on electrode wear rate (EWR) and material removal rate (MRR) have been examined. The experimental results indicate that higher pulse on time, lower pulse off time, 100 v to 110 v for voltage and current at the range of 8 to 9 A are the adequate selection to achieve higher MRR and lower EWR

Effect of Electrode Material and Electrical Discharge Machining Parameters on Machining of CO-CR-MO

The adequate selection of machining parameters is of prime importance to take into the account in of advanced engineering materials. The main focus of this experimental study is to observe the effect of electrode material and machining parameters viz. peak current, main voltage and duty factor on EDM of Cobalt-Chromium-Molybdenum (Co-Cr-Mo) using copper and brass electrodes. The findings highlight that electrode material significantly affects the process performance with respect to material removal rate and electrode wear. Better performance and higher efficiency is achieved by copper electrode. Peak current, voltage and duty factor play important roles in EDM performance and efficiency in terms of reducing machining time and improve tool utilization time and life

Thermal Performance and Numerical Simulation of the 1-Pyrene Carboxylic-Acid Functionalized Graphene Nanofluids in a Sintered Wick Heat Pipe

Experimental and numerical modeling of a heat pipe included with a phase change heat transfer was developed to assess the effects of three parameters of nanofluid, heat pipe inclination angles, and input heating power. Distilled water (DW) and 1-pyrene carboxylic-acid (PCA)-functionalized graphene nanofluid (with concentrations of 0.06 wt%) were used as working fluids in the heat pipe. A computational fluid dynamic (CFD) model was developed for evaluation of the heat transfer and two-phase flow through the steady-state process of the heat pipe. It was found that inclination significantly affects the heat transfer of the heat pipe. Maximum increment of thermal performance in the heat pipe reached 49.4% by using 0.06 wt% of PCA-functionalized graphene as working fluids. The result associated with this comparison indicates that the highest deviation is less than 6%, consequently confirming that the CFD model was successful in reproducing the heat and mass transfer processes in the DW and nanofluids charged heat pipe. The results of CFD simulation have good agreement between predicted temperature profiles and experimental data