Effect of cutting parameters on surface roughness in dry drilling of AISI D2 tool steel by using Taguchi Method

Hard drilling of AISI D2 reportedly produce accelerated wear to the cutting tool that detrimental to the surface finish. This paper presents the effect of drilling tool and drilling parameters by using Taguchi method to produce minimum surface roughness under dry conditions. The experiments were conducted using high speed steel (HSS) based drilling tools, coated with various coating layer (uncoated, TiN and TiCN) on material AISI D2 tool steel. Two cutting parameters, spindle speed and feed rate, each at three levels were considered. An L9 array, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to analyze the significant and percentage of each parameters for minimum surface roughness. The results revealed that the drilling tools gave main affects the surface roughness based on the highest percentage distribution (95%), followed by the spindle speed (3%) and feed rate (0.4%). Further, the results of ANOVA indicated that the combination of optimum parameter recorded as drilling tools HSS-TiCN with spindle speed of 680 rpm and feed rate of 206.25 mm/min

Effect of Cutting Parameters on Surface Roughness in Dry Drilling of AISI D2 Tool Steel by Using Taguchi Method

Hard drilling of AISI D2 reportedly produce accelerated wear to the cutting tool that detrimental to the surface finish. This paper presents the effect of drilling tool and drilling parameters by using Taguchi method to produce minimum surface roughness under dry conditions. The experiments were conducted using high speed steel (HSS) based drilling tools, coated with various coating layer (uncoated, TiN and TiCN) on material AISI D2 tool steel. Two cutting parameters, spindle speed and feed rate, each at three levels were considered. An L9 array, the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to analyze the significant and percentage of each parameters for minimum surface roughness. The results revealed that the drilling tools gave main affects the surface roughness based on the highest percentage distribution (95%), followed by the spindle speed (3%) and feed rate (0.4%). Further, the results of ANOVA indicated that the combination of optimum parameter recorded as drilling tools HSS-TiCN with spindle speed of 680 rpm and feed rate of 206.25 mm/min

Moisture Absorption Effects on Interlaminar Fracture Toughness of Woven Glass/Epoxy Composite Laminates

International audienceno abstrac

Moisture Absorption Effects on Interlaminar Fracture Toughness of Woven Glass/Epoxy Composite Laminates

International audienceno abstrac

Damage progression in BGA solder joints during board-level drop test

This study examines the dynamic fracture propagation experienced by critical solder joints in a BGA test package during board-level single drop test. An Input-G loading method is employed to simulate a drop test condition with a peak acceleration of 1500G within a time duration of 0.5 ms. Unified inelastic strain model (Anand) describes the strain rate-dependent response of the SAC405 solder material. Damage process in the brittle solder/intermetallic (IMC) interface is predicted using cohesive zone model. Results show that the first board deflection mode induces tensile stresses on the BGA package. The most critically strained solder joint only begins to experience the load (stress) at 0.06 ms following the applied impulse load. Calculated stress can reach up to 68 MPa at such high impact straining rate. The highest inelastic strain rate experienced by the most critical solder joint is 66.7 sec-1, thus solder/IMC interface fracture is likely the dominant fracture mode, as observed experimentally. Limited propagation of fracture region is predicted during the simulated single board-level drop test. However, damage is predicted to propagate earlier in solder joints located along the outer row of the array parallel to the shorter length of the test board. The shape of the interface crack front can be inferred from the contour of damage/undamage solder/IMC interface region of fractured solder joints

Fatigue failure processes in pb-free solder joints using continuum damage and cohesive zone models

The mechanics of failure in a solder joint under cyclic mechanical loading is quantified and described in this paper. It is postulated that fatigue failure of the solder joint occurs through simultaneous competitive mechanisms of cyclic damage processes occurring through the bulk solder and across solder/IMC interface. Progressive damage in the bulk solder joint is described using continuum damage model while cohesive zone model simulates the fracture process of the solder/IMC interface. For this purpose, a single-solder joint assembly with Sn-4Ag-0.5Cu (SAC405) solder and SAC405/Cu6Sn5 interface is modeled using finite element (FE) method. Unified inelastic strain model (Anand’s) with optimized parameter values for SAC405 solder represents the strain rate-dependent response of the solder. Cyclic plastic work-based phenomenological continuum damage model and cyclic stress- and energy-based cohesive zone model are employed to simulate damage response of the bulk solder and solder/IMC interface, respectively. Cyclic displacement loading (Δδ = 0.003 mm, R = 0) is prescribed to the edge of the “rigid” tool. Results show that the solder/IMC interface fatigue cracking dominates the fracture process. Fatigue crack initiated at the leading edge of the solder/IMC interface on the tool side of the assembly after accumulated 18 fatigue cycles. Simultaneously, inelastic strain accumulates at the critical material point with a decreasing rate. The predicted bending stress with opposing tensile and compressive stress region shall favor shear-driven fatigue crack diagonally across the bulk solder

Adhesive bonding characterization of composite joints

International audienceno abstrac

Numerical simulation of mode I delamination of multidirectional composites with fibre bridging effect

International audienceno abstrac