Study On Creep Behavior Of Aluminum Alloys Under Tension/Compression Stress

The successive launch of the Material Genome Project in various countries makes the development of new material property testing methods suitable for high-throughput testing urgent.Creep data,as an indispensable part of big material gene data,are characterized by long testing time and high testing cost,which makes creep testing especially need the development of new testing methods.As one of the important directions for the development of high-throughput creep test equipment,the compression creep test has many advantages that the tension creep test cannot have in the high-throughput test operation.For example,the material generally does not break during the compression test.There will not be necking(true stress),and it is easier to achieve multi-stations in the compression test.Using compression creep testing instead of the traditionally used tension testing method can give the goal of high-throughput quantification of creep testing a chance to be achieved.However,there is not much research on tension creep and compression creep anisotropy.The direct use of compression creep test instead of tension creep test still lacks relevant theoretical support,and how to use the data obtained through high-throughput test equipment testing,to obtain the same or more material-based information as the traditional tension tests is also an important issue,which urgently needs to be resolved in the development of creep test equipment.In this paper,we will conduct a systematic tension creep and compression creep test on the three materials of pure aluminum 1060,aluminum alloy 2024 and aluminum alloy 5083,and obtain the data of tension creep test and compression creep test through analysis and comparison.According to the different creep mechanism of the material,the influence of the test direction on the creep behavior of the metal material is analyzed independently and specifically.Then,through the establishment of constitutive models and other mathematical methods,scientifically and digitally compare the similarities and differences of the behavior of metal materials in tension creep test and tension creep test,which is the interoperability of compression creep test data and tension creep test data providing theoretical proof.The main work completed in this article are:(1)Tension creep and compression creep tests under various test conditions were carried out on pure aluminum 1060,aluminum alloy 2024 and aluminum alloy 5083,and the test result data were plotted into curves.Comparison of the creep curve found that in the test,the creep of 1060 pure aluminum is not sensitive to the direction of creep stress,and the tension and compression creep behavior has a high similarity within the range of stress conditions.While the tension and compression creep behavior of 5083 aluminum alloy and 2024 aluminum alloy are significantly different,which show obvious asymmetry.(2)Through the establishment of a unified constitutive model of 1060 pure aluminum and 5083 aluminum alloy tension and compression creep,it is found that the current classic creep unified constitutive model has a high degree of matching with the tension test,but it is not suitable for use in prediction of compression creep behavior.(3)By analyzing the experimental data of 1060 pure aluminum and 5083 aluminum alloy,combined with the parameter relationship of the model,the original creep constitutive model was supplemented with parameters.Based on this,a composite constitutive model suitable for both tension and compression creep is established in this paper.