C. H. Che Hassan

Case report of ruptured non-communicating right rudimentary horn pregnancy: an acute emergency.

Ruptured pregnancy in the rudimentary horn of women who have had a vaginal delivery is rare and unpredictable. However, when undiagnosed, this condition could lead to maternal morbidity and mortality. We report a pregnancy at 19 weeks gestation presented with acute abdomen and hypovolemic shock. She was initially thought to have an intrauterine pregnancy with the provisional diagnosis of a ruptured uterus. Intraoperatively, a ruptured non-communicating right rudimentary horn with ex utero pregnancy was discovered.

Tool Wear of PVD Coated Carbide Tool when Finish Turning Inconel 718 under High Speed Machining

This paper reports the results of an experimental works, where Inconel 718, a highly corrosive resistant, nickel-based super alloy, was finish-turning under high speed conditions. The machining processes were carried out at three different cutting conditions (DRY, MQL 50 ml/h and MQL 100 ml/h), three levels of cutting speed (Vc=90, 120 and 150 m/min), two levels of feed rate (f=0.10 and 0.15 mm/rev) and two levels of cutting depth (d=0.30 and 0.50 mm). The tool wear and flank wear progression were monitored, measured and recorded progressively at various time intervals. The experiments indicated that MQL condition performs better than dry condition in term of tool life. Most of the tool failures during machining were due to gradual failure where abrasive and notching wear on the flank face was the dominant followed by, fracture on the flank edge and nose radius. Tool failure due to crater wear was not significant. Wear mechanism such as abrasive and adhesion were observed on the flank face and diffusion wear was observed on the rake face.

Cutting force analysis when milling Ti-6Al-4V under dry and near dry conditions using coated tungsten carbides

The effectiveness of the usage of coolant in high speed machining of highly reactive material like titanium and its alloys is still far away uncertain. For this reason, it is wiser to study the effectiveness of MQL under transient cutting speed before we go to the high speed machining. This paper discusses the effect of MQL on the machinability of Ti-6Al-4V by using PVD coated cemented carbide tools. The machinability of Ti-6Al-4V was investigated based on the effect on cutting force and the tool life. The performance of PVD coated cemented carbide tool was investigated at various cutting condition. Completely dry machining and near dry (MQL) were applied in this experiment. For near dry machining, two levels of coolant flow rate were investigated, 50 and 100 mL/H. The effectiveness of mist coolant was tested at three different levels of cutting speed, 120, 135 and 150 m/min. Application of mist coolant is more significant at cutting speed of 135 m/min. At this speed longer tool life was obtained when more coolant was applied. No significant effect of the cutting speed and coolant flow rate on the surface roughness. Surface roughness is more sensitive to the feed rate and the depth of cut. No significant effect of application of MQL on cutting force at early stage of machining. MQL seems to be more affective when tools start worn out where greater contact area between tool and work piece occur to give better lubrication effect.

Study on drilling induced delamination of woven kenaf fiber reinforced epoxy composite using carbide drills

In this research study, it presents the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates when using the carbide drill bits. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated carbide drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs. The results indicated that the drill diameter has a significant influence on the delamination when drilling the woven kenaf fiber reinforced epoxy composites.

Wear Mechanism of Chemical Vapor Deposition (CVD) Carbide Insert in Orthogonal Cutting Ti-6Al-4V ELI at High Cutting Speed

The performance of Chemical Vapor Deposition (CVD) carbide insert with ISO designation of CCMT 12 04 04 LF, when turning titanium alloys was investigated. There were four layers of coating materials for this insert i.e.TiN‐Al2O3‐TiCN‐TiN. The insert performance was evaluated based on the insert’s edge resistant towards the machining parameters used at high cutting speed range of machining Ti‐6Al‐4V ELI. Detailed study on the wear mechanism at the cutting edge of CVD carbide tools was carried out at cutting speed of 55–95 m/min, feed rate of 0.15–0.35 mm/rev and depth of cut of 0.10–0.20 mm. Wear mechanisms such as abrasive and adhesive were observed on the flank face. Crater wear due to diffusion was also observed on the rake race. The abrasive wear occurred more at nose radius and the fracture on tool were found at the feed rate of 0.35 mm/rev and the depth of cut of 0.20 mm. The adhesion wear takes place after the removal of the coating or coating delaminating. Therefore, adhesion or welding of titanium...