Transition Depth Research Articles

Subduction erosion and basal accretion in the Central Chile subduction wedge inferred from local earthquake tomography

We analyze records of ambient seismicity from Central Chile to investigate mechanisms of tectonic erosion and accretion in an Andean margin. The seismograms were recorded by a temporary network of 39 stations deployed between 32.5°S and 34.0°S from April to November 2017. We employ an automatic earthquake catalogue generator to estimate 8463 P-wave and 5482 S-wave arrival times from 924 hypocenters, which were then used to jointly determine hypocenters and 3D models of Vp and Vp/Vs. Previous investigations of the nearby Illapel region suggest that the Coastal Cordillera acts as a subduction wedge, at the bottom of which are accreted crustal slices detached from the overriding plate by tectonic erosion. These slices may be subducted beyond the downdip frictional limit in a way that differs from a traditional orogenic wedge (type A-subduction). Our results reveal a wedge geometry with: (1) body wavespeed anomalies near the interplate contact below 30 km depth, which we interpret as accretionary complexes formed by basal accretion of crustal slices, and (2) latitudinal differences of those anomalies, which we attribute to eroded material from both plates that changes the basalt-eclogite transition depth in the subducted Nazca plate. Based on these, we infer that the development of this basal accretionary complex by subduction erosion could be responsible for the uplift of Coastal Cordillera in Central Chile, and that the retroshear zone of the subduction wedge is controlled by local conditions inside the mantle wedge. Moreover, we suggest that the accretionary complex beneath the Central Chile subduction wedge behaves as seismic barrier that can explain the 1985 Mw 8.0 Valparaíso earthquake slip distribution and the southeastward migration of aftershocks of 2017 Mw 6.9 Valparaíso earthquake. Finally, we suggest that the subduction wedge influences continental structures on a scale of millions of years.

An analytical force and energy model for ductile-brittle transition in ultra-precision grinding of brittle materials

The critical grinding depth of ductile-brittle transition is an important processing parameter to guarantee brittle materials machining in ductile mode. Nevertheless, it is a difficult task to predict the critical grinding depth considering multiple grain interactions due to the random grain distribution on the wheel. In our paper, a novel grinding force and energy model is established to predict the critical grinding depth with considering the random interactions between multiple grains, and experimental validations are carried out on single crystal silicon. In this process, the grain-workpiece interactions are explored by the actual grain protrusion heights and random grain distribution. The surface generation mechanisms of the ductile-brittle transition are comprehensively investigated by applying the numerical and experimental methods. It shows that the plastic ploughing and brittle fracture are the dominant material removal modes when grinding brittle materials. Moreover, validation experiment results indicate that the proposed model could accurately predict the realistic critical grinding depth with an average deviation of less than 9.2%. Finally, based on the proposed model, the influence of grinding conditions on the critical grinding depth are investigated in detail. The critical grinding depth increases with increasing grinding speed, while decreases with increasing feed speed. Hence, this research not only provides a new method for predicting the critical grinding depth, but also enhances the understanding of the ductile-brittle transition mechanism in brittle materials machining.

Homogenization of a two-phase flow accompanied by dissociation of a gas hydrate in a fractured porous medium

A homogenized model of non-isothermal compressible two-phase flow accompanied by dissociation of a gas hydrate in a fractured porous medium is derived. The equations of the homogenized model contain non-local in time source terms corresponding to the contribution of the gas hydrate in the matrix blocks. The model of phase behavior of a gas hydrate is used that admits coexistence of the hydrate and products of its decomposition in a finite region of the phase diagram. This possible behavior is a consequence of non-linearity of the skeleton potential dependence on the depth of phase transition.

Free surface aeration and development dependence in chute flows

The microscopic description of the mixture behaviour of air–water flow remains a challenge. It is not clear how to represent a complex two-phase interaction with the turbulent air–water structure development process. In this study, based on the air–water mixing fluctuation properties in self-aerated chute flows, a prediction model of air concentration distribution related to a theoretical transition depth is developed. The air–water turbulent mixing analysis reveals that the mixture flow depth, at which the local air concentration is 0.5, represents the interior transition boundary. The agreement of the calculated results with the test data confirms that local water and air turbulent mixing through the free surface area should be equally considered. On the basis of the interior transition depth, the development of self-aeration mainly manifests as the air turbulent mixing process in the low aerated region, while the water turbulent mixing in the high aerated region remains mostly unchanged. A series of relationships concerning the development of self-aerated flows is proposed to enable quantitative estimations in practical applications of water engineering.

Thermodynamic Characteristics of cold and hot non-condensable gases simultaneously flowing along vertical wellbore

In recent years, thermal non-condensable gas injection was widely used in petroleum industry to enhance oil recovery. However, the research on the heat transfer process and thermodynamic characteristics analysis along wellbore is almost in blank under the condition of cold and hot non-condensable gases simultaneously flowing in wellbore. In this paper, a complicated mathematical model was established considering simultaneous hot and cold gases injected into tube and annulus. Meanwhile, a coupling calculation method was introduced based on temperature equations, pressure equations, and thermodynamic properties. The model can be used to analyze temperature and pressure distribution, the depth of phase transition, the heat transfer pattern and the thermodynamic characteristics. The accuracy of the model was verified and sensitivity analysis of some parameters was conducted. It is found that: (a) The injection method (hot N2 is injected into tube and cold CO2 is injected into annulus) is optimal, which produces fainter heat loss and maintains higher total energy; (b) Some factors, such as, the injection temperature, the injection mass ratio of hot and cold gases, and the injection velocity, have a dramatic effect on temperature and pressure distribution, fluid thermophysical parameters, and fluid phase state. (c) According to the calculation results, the optimal temperature of nitrogen is 350 °C, the optimal injection mass ratio of N2 to CO2 is 15:1, and the optimal injection velocity of CO2 is 120 t/d; (d) The temperature along wellbore changes intensively at the beginning of injection while it becomes stable when the injection time exceeds 10 days. The ingenious coupling model with intricate iterative processes can perfectly simulate the injection process of hot and cold non-condensable gases and obtain the temperature and pressure distribution along wellbore, which can provide tremendous guidance and assistance for injection operations in the oilfield.

The May 15, 2020 M 6.5 Monte Cristo Range, Nevada, earthquake: eyes in the sky, boots on the ground, and a chance for students to learn

ABSTRACT The M 6.5 earthquake that occurred in the Monte Cristo Range near Mina, Nevada on 15 May 2020 was exceptionally well-recorded with both seismic and geodetic instrumentation. The arid nature of the region also facilitated detailed ground mapping of the surface rupture. Here we integrate several independent data sets to illustrate the educational and research opportunities afforded by these rich data sets. We construct a series of models for slip at depth that are consistent with the satellite-derived geodetic data, the distribution of aftershocks, and the mapped surface rupture. We also show that the modelled depth of maximum slip is in good agreement with heat flow and laboratory data on quartz rheology defining the depth of the brittle-ductile transition. The Monte Cristo Range earthquake also suggests new approaches to seismic hazard assessment may be required for earthquakes in rapidly evolving tectonic regions such as the Walker Lane and Eastern California shear zone.

Brittle-Ductile Transition and Nano-Surface Generation in Single-Point Diamond Turning of Single-Crystal Germanium

Single-crystal germanium (Ge) has been widely used in infrared optics and ultra-precision components, however, the appearance of alternating brittle and ductile fan-shaped patterns on machined surfaces seriously affects the machined surface quality. The present research focused on the brittle-ductile transition and its effect on the nanosurface generation in single-point diamond turning (SPDT) of (100), (110) and (111) crystal planes of Ge. Face cutting and plunge cutting experiments were performed, the surface anisotropy and brittle-ductile transition regime during cutting were analyzed, and the evolution of crystalline structure were discussed with molecular dynamics (MD) simulation. Theoretical and experimental results show: (1) The anisotropy of the machined surface is closely related to the atomic arrangement order and lattice structure. The anisotropy of the (111) crystal plane is stable while the (110) is unstable. (2) The critical length and depth of both the elastic-ductile and brittle-ductile transition are anisotropic; the depth and length of brittle regions are shallower and shorter than those of ductile regions and proportional to the tool edge radius. (3) The critical depth and thrust force of the elastic-ductile transition obtained in MD simulation can be employed to predict the changing trend of the brittle-ductile transition. (4) The thickness of amorphous layer produced on the machined surface is proportional to the ratio of cut depth to tool edge radius. The crystal orientation of the (111) crystal plane shows the best cutting performance. This paper provides deep insight into the brittle-ductile transition and nanosurface generation in SPDT of Ge.

Investigation of material removal mechanisms and ductile-brittle transition zone of zirconia ceramics sintered at various temperatures

Sintering is a comprehensive process that involves the complex evolution of material microstructures and properties, being recognized as a critical factor to improve the machinability of ceramics. The present work aims to address the evolution of the material removal mechanisms of the 3mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) during the sintering process based on the micro scratching tests. The impacts of sintering temperatures on the material removal behaviors, including scratching forces, scratch morphologies, specific scratching energies, and critical transition depths, were rigorously studied. The acquired results indicate that the intergranular bonding strength is a critical factor that determinines the material removal mechanisms of 3Y-TZP, and 1100°C signifies the transition threshold for the material removal mode. After 1100°C, the material removal mechanism has gradually converted into the typical ductile-brittle removal regime. Moreover, the critical depth in ductile regime at 1200°C is about 1.89 times that at 1500°C, and the critical depth of ductile-brittle transition at 1200°C is approximately 2.08 times that at 1500°C.

Cutting force as an index to identify the ductile-brittle failure modes in rock cutting

Rock failure modes exist a transition from ductile to brittle with the increase of cutting depths. Further insight into the determination of critical transition depth is of great significance to optimize the design of cutting tools and operational parameters . In the present study, a novel method for identifying rock failure modes is proposed based on the evolution of cutting force. Furthermore, a series of experiments were conducted to validate this method and investigate the critical depth under different experimental conditions. Firstly, we calculate the cutting force difference (Δ F ) from peak to valley and its variation rate ( Ra ). Then, Ra and Δ F are fitted linearly, and the slope of the fitting line ( Sl Ra ) is determined. According to the experimental results, rock breakage is a process involving continuous changes in failure modes. At shallow cutting depths, Sl Ra is close to zero, indicating the domination of ductile failure . Then Sl Ra rises with the increase of cutting depths, indicating that the proportion of brittle failure becomes higher. Such region is generally defined as a transition region. Once cutting depths exceed the critical depth, effects of ductile failure can be ignored and Sl Ra tends to be stable. The higher rock brittleness and smaller back rake angles result in a reduction of critical depth. In addition, the critical transition depth can be correlated with some parameters such as the distribution of cuttings and the number of valleys in cutting force. Our current study helps to identify rock failure modes and provides an in-depth understanding about the critical depth.

Determination of the optimal transition point between a truck and shovel system and a semi-mobile in-pit crushing and conveying system

One of the most challenging aspects in semi-mobile in-pit crushing and conveying (SMIPCC) system design is determining the optimum depth at which to change from a purely truck-based haulage system to a conveyor-based haulage system. We used scenario analysis to determine the optimum transition depth between a truck and shovel (TS) system and a SMIPCC system. Traditional pit-limit algorithms were used to generate the final pit limit on a copper deposit, which was then divided into four pushbacks. The final operating pushbacks (phases) were designed for both TS and SMIPCC. The end depths for each phase are viewed as candidate transition points to switch from the TS to SMIPCC haulage system. Economic calculations were applied for five different scenarios, including adopting SMIPCC from the outset (pure SMIPCC), after the first, second, and third phases, and finally not using the SMIPCC system (pure TS) at all. The analysis indicates that the second scenario, at a depth of 335 m, results in the lowest cumulative discounted cost (CDC). In this case, the CDC is 17.6% lower than that for the pure TS scenario and 10.7% lower than for the pure SMIPCC system scenario.

A Self-Established "Machining-Measurement-Evaluation" Integrated Platform for Taper Cutting Experiments and Applications.

Taper-cutting experiments are important means of exploring the nano-cutting mechanisms of hard and brittle materials. Under current cutting conditions, the brittle-ductile transition depth (BDTD) of a material can be obtained through a taper-cutting experiment. However, taper-cutting experiments mostly rely on ultra-precision machining tools, which have a low efficiency and high cost, and it is thus difficult to realize in situ measurements. For taper-cut surfaces, three-dimensional microscopy and two-dimensional image calculation methods are generally used to obtain the BDTDs of materials, which have a great degree of subjectivity, leading to low accuracy. In this paper, an integrated system-processing platform is designed and established in order to realize the processing, measurement, and evaluation of taper-cutting experiments on hard and brittle materials. A spectral confocal sensor is introduced to assist in the assembly and adjustment of the workpiece. This system can directly perform taper-cutting experiments rather than using ultra-precision machining tools, and a small white light interference sensor is integrated for in situ measurement of the three-dimensional topography of the cutting surface. A method for the calculation of BDTD is proposed in order to accurately obtain the BDTDs of materials based on three-dimensional data that are supplemented by two-dimensional images. The results show that the cutting effects of the integrated platform on taper cutting have a strong agreement with the effects of ultra-precision machining tools, thus proving the stability and reliability of the integrated platform. The two-dimensional image measurement results show that the proposed measurement method is accurate and feasible. Finally, microstructure arrays were fabricated on the integrated platform as a typical case of a high-precision application.

Focused Penetrative Plumes: A Possible Consequence of the Dissociation Transition of Post‐Perovskite at ∼0.9 TPa in Massive Rocky Super‐Earths

AbstractBased on the standard view of depth‐increasing viscosity in the mantle of rocky planets, convection in the deep mantle of these planets is expected to become less likely as the size of planet increases. However, a recent theoretical study suggests that above 100 GPa pressure, the mantle viscosity can instead decrease with pressure at higher depths. We explore the potential impact of this type of viscosity structure on the nature of mantle convection in a super‐Earth planet of size GJ 876 d with a mass of ∼7.33 M⊕ (M⊕: Earth's mass). The pressures at the bottom of the mantle of GJ 876 d allow MgSiO3 post‐perovskite to dissociate into magnesium oxide (MgO) and relatively highly oxidized magnesium silicate MgSi2O5 at 0.9 TPa with highly negative Clapeyron slope. Our 3D‐spherical numerical model results suggest that for sufficiently low values of viscosity at the transition depth, a vigorous layered mantle convection may develop at the bottom of GJ 876 d‐size super‐Earth. Focused penetrative plumes originating from the deep mantle layered region can survive and stabilize over very long geological timescales and reach to the surface, which may induce unique circumstances of volcanism and tectonic activity.

Fundamental study on material removal mechanism in single-crystal germanium

In this study, vary-loads and const-load nano-scratching tests were performed to investigate the material removal mechanism in single-crystal germanium. Based on the indentation size effect, the cutting force in the ductile regime was modelled analytically considering the elastic recovery and sliding friction. Subsequently, a novel specific cutting energy (SCE) model was proposed to quantitatively determine the ductile to brittle transition (DBT) depth. The surface topography of the workpiece was observed and measured using a scanning electron microscope (SEM) and an atomic force microscope (AFM). The surface morphology revealed the existence of a ductile regime, DBT regime, and brittle regime in the nano-scratching process. The DBT depth was calculated analytically using the proposed SCE model, which had a prediction error of less than 4.02%. Thus, the model results were in good agreement with the experimental results. The phase transitions of different material removal modes were characterised using Raman spectroscopy, which revealed that the phase transition from the crystalline phase to the amorphous phase dominated the material removal process. In addition, the feasibility of high-efficiency machining by increasing the cutting speed was verified: the surface integrity improved and the subsurface damage reduced at high cutting speeds. These findings provide a fundamental understanding of the ductile regime machining process for single-crystal germanium.

Temperature Dependent Minerals as a Tool to Prove High Temperature of a Blind Geothermal System. Case Study: Well “X” at Java Island of Indonesia

Geology and mineral alteration are studied to review the equilibrium of blind geothermal system in Java Island, Indonesia. The “X” well is a slim hole well that has been drilled to 2000 mMD. Indication of high-temperature geothermal system is observed by pressure-temperature survey and mineral alteration recovered by full core from surface to bottom (2000 mMD). Geologically, this geothermal prospect is situated on a caldera system with the volcanism started since the Lower Pleistocene related to the early stages of magmatic activity of the modern Sunda arc. Multiple eruptions associated with the pre-caldera, syn-caldera, and post-caldera volcanism deployed rock formation which are consisted of andesitic lava series, volcanic breccia, and pyroclastic. Based on the study of mineral alteration, three hydrothermal alteration zones are defined from temperature-dependent minerals to predict reservoir temperatures, smectite zone (T<180°C) from the surface down to 1200 mMD, transition zone (T = 180-220°C) down to 1383 mMD, and illite zone (T>220°C) down to 2000 mMD. Moreover, the hydrothermal alteration zone is mainly used to estimate the depth of clay cap, transition, and reservoir zone for a future appraisal well. Correlating the temperatures and hydrothermal alteration zones could help in proving a high-temperature geothermal system especially in a blind geothermal system.

Ultra-precision diamond turning of ZnSe ceramics: Surface integrity and ductile regime machining mechanism

ZnSe ceramics has extensive applications in infrared imaging and laser systems. However, as a soft–brittle optical material, the mechanism of material removal and surface defects formation in ultra-precision diamond turning have not been clarified. In the present study, novel taper cutting tests were conducted to determine the ductile–brittle transition depth. Furthermore, the precondition for achieving ductile mode machining was revealed by comparing the maximum undeformed chip thickness and ductile–brittle transition depth. The effect of feed rate on surface roughness, surface quality, phase transition, and subsurface damage were systematically investigated. With the aid of cross-sectional TEM, the material removal mechanism in the ductile regime was revealed first, and the results indicated the formation of high-density dislocations, stacking faults, and deformation twins coordinating to promote ductile deformation. The study has provided insight into ductile regime machining mechanisms of ZnSe ceramics in the ultra-precision diamond turning process.

Clarifying source assemblages and metasomatic agents for basaltic rocks in eastern Australia using olivine phenocryst compositions

Many Cenozoic basaltic rocks in Eastern Australia exhibit an age-progressive trend from north to south, leading to the suggestion that one or more mantle plumes passed beneath the Australian plate. Trace element patterns indicate that the source regions have been metasomatised by infiltrating melts, but the source rock assemblages have never been closely identified. Here, trace element analyses of olivine and whole rock geochemistry for several occurrences in New South Wales (Dubbo, Ebor, Bingara/Inverell, and Barrington) are combined with samples from Buckland (Queensland) to characterize the mineralogy of the source and identify the nature of the melts that caused the metasomatic enrichment. According to Ni/Mg against Mn/Fe and Zn/Fe ratios in olivines, Zn/Fe and FC3MS (FeOT/CaO-3*MgO/SiO2) parameters in whole rocks, tholeiite, alkali basalt, and basanite rich in olivine xenocrysts from Dubbo were derived from pyroxenite-dominated mixed source, mixed pyroxenite + peridotite source, and peridotite-dominated source, respectively. Similarly, basalts from Ebor and Bingara/Inverell are suggested to originate from a mixed pyroxenite + peridotite source based on their high FC3MS values. In contrast, the source of basanite and picrobasalt from Barrington was peridotite-dominated with less pyroxenite. High Li and Zn in olivines, high P2O5/TiO2 and Zr/Hf at low Ti/Eu in whole rocks illustrate that the pyroxenite sources of basanites from Bingara/Inverell, Barrington, Dubbo and Buckland resulted from variable degrees of carbonatitic metasomatism. Partial melting of peridotite metasomatised by carbonatite melts at around the spinel-garnet peridotite transition depth produced basalts and basanites from Dubbo, Ebor, Bingara/Inverell, Barrington and Buckland. Carbonatitic metasomatism is widespread in the eastern Australian mantle lithosphere, concentrated on the ledge of the thick lithosphere beneath the Australian continent that stretches from Queensland, through New South Wales to Victoria.

Characteristics of interface defeat and penetration during the impact between a ceramic armor and a long-rod projectile

Interface defeat/dwell can effectively improve the anti-penetration performance of a ceramic armor at certain degree, which attracts the attention from researchers all over the world in recent years. Experiments on a ceramic armor subjected to the impact of a long-rod projectile (LRP) were carried out to investigate the characteristics of interface defeat and penetration during the impact in this paper. A theoretical model for the penetration process of a LRP into a ceramic target with semi-finite thickness at different impact velocities was established by considering interface defeat/dwell to study quantitatively the effect of interface defeat/dwell on the penetration. The theoretically calculated results on dwell/penetration transition velocity, dwell time, penetration velocity and depth of penetration agree well with the experimental data, which proves that the established theoretical model is accurate. The influences of the projectile and ceramic materials on the interface defeat/dwell and penetration were analyzed. Both the experimental results and the calculated results by the theoretical model show that the interaction between LRPs and ceramics transfers from interface defeat to penetration when the impact velocity increases. It also indicates that the established theoretical model can depict the interaction modes of ceramics and LRPs under different impact velocities. The yield stress and density of the projectile materials play a coupling role in the interaction between LRPs and ceramics when the interface defeat/dwell occurs. The higher the yield strength and density of the projectile materials, the shorter the dwell time and the higher the penetrating ability of the projectile. The higher the dynamical yield strength of the ceramics, the more markedly the interface defeat/dwell and the higher the anti-penetration ability of the ceramic armors. The established theoretical model in consideration of interface defeat/dwell can partially reveal the mechanism of the interface defeat, and it can provide a reference for the design of ceramic composite targets.

Study on the surface formation mechanism in scratching test with different ultrasonic vibration forms

Rotary ultrasonic machining (RUM) has been considered as an effective approach in the manufacturing of advanced materials such as ceramic matrix composite (CMC). However, the distinct removal mechanisms in RUM with different vibration forms has not been elucidated, which hinders the adoption of RUM technology in the field of material processing. In this research, the ultrasonic-assisted scratching tests of CMC were conducted to reveal the fundamentals of material removal and surface formation. Based on the kinematics of RUM processes, the vibration effects exerted in cutting areas were clarified as impact-separation and reciprocating-polishing, thus two types of diamond indenters have been specially designed for the intermittent and continuous scratching tests, respectively. The scratching force, friction factor and grooves morphology have been analyzed and compared with that of the conventional scratching without vibration. For the intermittent scratching with vertical vibration, it was found that the high frequency impact-separation between indenter and workpiece increased the critical penetration depth of ductile-brittle transition, which can help restrain the cracking defects of CMC. For the continuous scratching with tangential vibration, the overlapping rate was firstly proposed to evaluate the effect of reciprocating polishing. It was shown that higher overlapping rate and larger dynamic shear angle can be achieved by matching the scratching velocity with vibration frequency, which is conducive to obtaining even fiber fracture and better surface integrity. Due to the minimal volume of material removed in each vibration cycle, the scratching resistance was significantly lowered with smaller fluctuation under both vibration forms. Moreover, the diminishing of vibration effectiveness at certain scratching parameters was also discussed. This research work brings in a better understanding on the material removal mechanisms under different effects of ultrasonic vibration, which can provide a guidance for the design and optimization of the vibration assisted processing of advanced materials.

Backstroke to Breaststroke Turning Performance in Age-Group Swimmers: Hydrodynamic Characteristics and Pull-Out Strategy.

We compared the hydrodynamic characteristics and pull-out strategies of four backstroke-to-breaststroke turning techniques in young swimmers. Eighteen 11 and 12-year-old swimmers participated in a 4 week intervention program including 16 contextual interference sessions. The hydrodynamic variables were assessed through inverse dynamics, and the pull-out strategy kinematics were assessed with tracking markers followed by 12 land cameras and 11 underwater cameras. Swimmers randomly completed sixteen 30 m maximal backstroke-to breaststroke-open, somersault, bucket and crossover turns (four in each technique) with a 3 min rest. The data showed higher drag force, cross-sectional area and drag coefficient values for the first (compared with the second) gliding position. The crossover turn revealed the highest push-off velocity (2.17 ± 0.05 m·s−1), and the somersault turn demonstrated the lowest foot plant index (0.68 ± 0.03; 68%), which could have affected the first gliding, transition and second gliding depths (0.73 ± 0.13, 0.86 ± 0.17 and 0.76 ± 0.17 m). The data revealed the consistency of the time spent (4.86 ± 0.98 s) and breakout distance (6.04 ± 0.94 m) among the four turning techniques, and no differences were observed between them regarding time and average velocity up to 7.5 m. The hydrodynamic characteristics and pull-out strategy of the backstroke-to-breaststroke turns performed by the age group swimmers were independent of the selected technique.

Examination the cosmic ray muon attenuation by heavy metal alloys

The ability of a muon telescope to detect high dense metal elements was experimentally determined in previous works. Recently, the muon absorption has become one of the most important data in the tomography technique. In the present study, the absorption coefficients of muon at ground level for heavy alloys, namely brass, steel and stainless steel have been successfully recorded. The experiment was performed in Bangi, Malaysia with coordinates of 101.78º E, 2.92º N and elevation of 30 m above sea level. Muon examination was made by muon telescopes contained of two Geiger-Muller detectors. The muon count rate graphs showed an initial increase, followed by a transition depth and then a decrease with the continuous increase of the alloys thickness. The transition points observed were reliable and consistent with the properties of the alloys. The absorption coefficient of brass was higher than the other alloys; therefore, brass could be detected by cosmic ray muons easily. The results confirmed that the larger the mass density of the alloy absorber, the higher the ability to absorb the muon. The attenuation stated by this experiment would be valuable for coming work on muon revealing procedures.