武汉理工大学材料概论期末试卷

武汉理工大学材料概论
期末试卷
-CAL-FENGHAI.-(YICAI)-Company One1
一、Fill in the blanks (1’×10 = 10’)
1. The four basic types of bonding arrangements which hold atoms toget her are the _________ bond,
_________ bond, ionic bond and the van der Waals forces.
2. One of the main factors on the brittle nature of glass is the _________ .
3. The small molecules in polymers are termed _________, the reactions by which they combine are
termed _________.
4. A property of a material is determined by analyzing the _________ of the material to some outside
influence, generally by means of a _________ standard test.
5. Hardened concrete should be _________, strong, watertight and resis tant to abrasion.
6. It is the behavior and properties of the _________ that generally contr ol the properties of composites.
7. _________ is not only one of the mos t abundant elements in the earth’s crust, but it is also the most abundant metal in the earth’s crust.
二、True or false (indicate with “√” or “×”, 1’×10 = 10’)
1. All amorphous materials are glasses.
2. Magnesium is the lightest of all structural metals.
3. Al2O3 纤维和Al 基体组成颗粒增强复合材料。

4. The constituent atoms of glass and ceramics are stacked together in a regular repeating pattern.
5. The weight ratio of water to cement in conc rete is called water-cement ratio.
6. The copper-
zinc alloys are referred to as brasses.
7. The basic unit of the traditional ceramic is the SiO4 tetrahedron. 8. 纤维增强树脂是一种复合材料，而混凝土不是复合材料。

9. The aluminum oxide is (Al2O3) is typical type of metal and is a good h eat and electric conductor. 10. The crystalline state of a solid is more sta ble than amorphous state.
三、Choose the right answer (1’×10 = 10’)
1. More than 90% of the glass in use is based on oxides and in particular _____. a. oxides b. salts c. calcium d. silica
2. A material that will not deform plastically under load is said to be ___ ___. Excessive cold working causes loss of ______. a. tough b. brittle
c. value
d. ductility
3. Most metals occur in nature as compounds which must be ____ to fre
e the metal. a. reduced b. oxidized c. extracted d. excavated
4. Polymers vary in their mechanical behavior depending on the degree of _____ , degree of crosslinking, and the values of Tg and Tm.
历史老照片不能说的秘密慈禧军阀明末清初文革晚清
a. structure
b. crystallinity
c. melting point
d.Tg
5. One of the main factors on the brittle nature of glass is the presence o
f ______. a. surface defect b ionic bonds c. chemical reaction d. physi cal properties 6. The two main raw materials for producin
g cement are li mestone and ______. a. iron b. aluminum c. coal d. clay
7. The ductility of a material is investigated with the _____ test. a. comp ression b. shear c. tensile d. torsion 8. 用铝合金制作门窗是利用铝合金_____的优点。

a. 不易腐蚀
b. 硬度较大
c. 熔点较低
d. 导热良
好 9. The chain polymerization starts with the _____ reaction.
a. initiation
b. addition polymerization
c. propagation
d. termination
四、Terms and definitions (4’×5 = 20’)
1. Polymer
2. Ductility
3. Free radical
4. Physical properties
5. Packin
g factor
五、Questions and replies (8’×4 = 32’)
1. How are the porosity defined in normal ceramics based on the connec tivity and how is the strength of ceramics affected by pores
2. How many kinds of composites can be classified based on the form of the matrix? Please list the factors influencing the properties of the poly mer-matrix composites.
3. Please explain why metals are good electrical conductors and most ce ramics are good electrical insulators in regard to their atomic bonding. 4 . 简述填料在复合材料中的作用。

六、Read and discuss (9’×2 = 18’)
1. Ceramic materials are generally things like tile, bricks, plates, glass, an
d toilets. They can b
e found in
products like watches (quartz tuning forks-
the time keeping devices in watches), snow skies (piezoelectric-ceramics that stress when a voltage is applied to them), automobiles (sp arkplugs and ceramic engine parts found in racecars), and phone lines. T hey can also be found on space shuttles, appliances (enamel coatings), a nd airplanes (nose cones). Depending on their method of formation, cer amics can be dense or lightweight. Typically, they will demonstrate excel lent strength and hardness properties; however, they are often brittle in nature. Ceramics can also be formed to serve as electrically conductive materials, objects allowing electricity to pass through their mass, or insul ators, materials preventing the flow of electricity. Some ceramics, like su perconductors, also display magnetic properties. Question:
Please explain the major advantages of ceramics that we consider when choosing the ceramic for certain applications and main disadvantage?
2. Strength test of concrete is undoubtedly the most common type of tes t to evaluate the properties of hardened
concrete. The compressive strength of concrete at 28 days is almost univ ersally adopted as the basis for structural calculations. It is also used to d esignate concrete. When concrete is placed on site, samples of concrete are taken to make cubes (or cylinders) that are cured in a specified condi tion and tested at different ages.
Question:
Please explain why the strength of concrete is generally used to evaluate the quality of hardened concrete.
标准答案（ A卷）
一、Fill in the blanks (1’×10 = 10’)
1. metallic, covalent
2. surface defect.
3. monomers, polimerization .
4. reaction, normalized
5. durable
6. inte rface
7.
Aluminum
二、True or false (1’×10 = 10’)
(×) (√) (×) (×) (√) (√) (×) (×) (×) (√)
三、Choose the right answer (1’×10 = 10’)
1. (d)
2. (b, d)
3. (a)
4. (b)
5. (a)
6. (d)
7. (c)
8. (a)
9. (a)
四、Terms and definitions (4’×5 = 20’)
1. Polymer: macromolecules built up by the linking together of large nu mbers of much smaller molecules.
2. Ductility: The property that allows a metal to deform permanently wh en loaded in tension.
3. Free radical: it is simply a molecule with an unpa ired electron.
4. Physical properties: The behavior of materials subjected to the action of temperature, electric or magnetic fields or light.
5. Packing factor: The ratio of the volume of all elementary particles per elementary cell to the total volume of the elementary cell.
五、Questions and replies (8’×4 = 32’)
1. Many applications that use advanced ceramics are limited by pores, w hich scatter light and make them opaque or translucent. Pores can also make the ceramic too brittle and ruin the flow of electrons and/or heat t hrough the material. Questions:
a. How are the porosity defined in normal ceramics based on the connec tivity
b. How is the strength of ceramics affected by pores
Answer:
a: There are two types of porosity. Open porosity refers to the network o f pores in a
material that is open to the surface. [2’] Closed porosity refers to those p ores that have become sealed within the grain structure [2’].
b: Pores affect the strength of ceramics in two ways. First, they produce stress
concentrations [2’]. Second, pores reduce the strength of ceramics beca use they reduce the cross-
sectional areas over which a load can be applied [2’].
2. Composite materials (or composites for short) are engineered materia ls made from two or more constituent materials with significantly differe nt physical or chemical properties which remain
separate and distinct on a macroscopic level within the finished structur e.
a. How many kinds of composites can be classified based on the form of the matrix?
b. Please list the factors influencing the properties of the p olymer-matrix composites.
Answers:
Three main groups: Polymer Matrix Composites (PMC’s), Metal Matrix C omposites (MMC’s), Ceramic Matrix Composites (CMC’s)[3’]
Factors determining the properties of the composite are:
(1) the properties of the fibre [1’]; (2) the properties of the resin [1’];
(3) the ratio of fibre to resin in the composite (Fibre Volume Fraction (F VF)) [2’]; (4) the geometry and orientation of the fibres in the composit
e [1’]
3. Please explain why metals are good electrical conductors and most ce ramics are good electrical insulators in regard to their atomic bonding. A nswer: Metals: metallic bonding, there are free electrons[3’]. The free movement of electrons accounts for the high electrical and heat conduct ivity of metals [2’]. Ceramics: ionic bonding and covalent bonding[2’], t here are no free electrons[1’].
4. 简述填料在复合材料中的作用。

答：填料可以提高复合材料的强度和刚度[2’]，提高复合材料的耐热性和冲击韧性[2’]，降低基体树脂的固化放热和固化收缩，以及提高制品的尺寸稳定性[2’]。

但填料的加入也会增加树脂体系的黏度，其适用的成型工艺受到一定程度的限制，且会对树脂的固化和储存期产生一定的影响[2’]。

六、Read and discuss (9’×2 = 18’)
3. Ceramics are all around us. This category of materials includes things li ke tile, bricks, plates, glass, and toilets.
Ceramics can be found in products like watches (quartz tuning forks-the time keeping devices in watches), snow skies (piezoelectric-ceramics that stress when a voltage is applied to them), automobiles (sp arkplugs and ceramic engine parts found in racecars), and phone lines. T hey can also be found on space shuttles, appliances (enamel coatings), a nd airplanes (nose cones). Depending on their method of formation, cer amics can be dense or lightweight. Typically, they will demonstrate excel lent strength and hardness properties; however, they are often brittle in nature. Ceramics can also be formed to serve as electrically conductive materials, objects allowing electricity to pass through their mass, or insul ators, materials preventing the flow of electricity. Some ceramics, like su perconductors, also display magnetic properties.
Question: please explain the major properties of ceramics that we consi der when choosing the ceramic for certain applications?
Answers:
Advantage: (1) extreme hardness [2’]; (2) heat resistance [2’]; (3) corrosi on resistance [2’]; (4) low electrical and thermal conductivity [2] Disavantage: low ductility or brittleness [1’]
4. Strength test of concrete is undoubtedly the most common type of tes t to evaluate the properties of hardened
concrete. The compressive strength of concrete at 28 days is almost univ ersally adopted as the basis for structural calculations. It is also used to d esignate concrete. When concrete is placed on site, samples of
concrete are taken to make cubes (or cylinders) that are cured in a specif ied condition and tested at different ages.
Question: please explain why the strength of concrete is generally used t o evaluate the quality of hardened concrete.
Answers:
(1) the strength of concrete in compression, tension, shear or a combina tion of these has a direct influence on the load carrying capacity of both plain and the reinforced structures [3’].
(2) of all the properties of hardened concrete, those concerning strength can usually be determined most easily [3’].
(3) by means of correlations with other more complicated tests, the resu lts of strength tests can be used as qualitative indications of other prope rties of hardened concrete
一、Fill in the blanks (1’×10 = 10’)
1. The advantage of microwave heating is that it is extremely _____ .
2. The mechanical properties of ceramics are good in______ , The g reatest weakness is______
3. Ferrous Alloys normally contains major phases, called austenite____ _, ______ , _______ , martensitic.
4. The components as well as the interface between them can usually be _____ identified.
5. Surface treatment of reinforcing materials is done to_________ the adhesion of fillers and fibers to matrix resin by________ the surface of the solid.
6. The properties of materials are defined by the nature of their chemica l bonds, their______ ordering and their ____ .
二、True or false (indicate with “√” or “×”, 1’×10 = 10’)
1. All amorphous materials are glasses.
2. Aluminum alloys offer superior specific strength in high temperatures.
3. The properties of crystals are different in various crystallographic dire ctions.
4. Titanium alloys have lower density and high strength.
5. Most of life and industrial glass are made from silica and silicate glasse s.
6. Magnesium is the lightest of all structural metals.
7. Glasses is made from elements, simple chemical compounds, complex organic molecules, salt mixtures and alloys.
8. Glass when newly formed, with a perfect surface, is very strong about five times as strong as steel. 9. MMC、PMC、
CMC are all composite, and matrix are metal, ceramic and organic polym er. 10. 玻璃化温度和熔点是表征聚合物热性能的重要指标。

.
三、Choose the right answer (1’×10 = 10’)
1. Which of the following descriptions would not be applicable to cerami cs?
a. Mixed ionic and covalent bonding
b. Brittle
c. Hard
d. Ductile 2 . 组成铸铁的基本元素是__________.
a. O;
b. C;
c. S;
d. Si;
e. Fe;
f. Al;
g. P 3. 低合金钢合金元素含量
______，而高合金钢_________。

a.<2%;
b.<5%;
c. >10%;
d.>13%
4. Hardened concrete should be durable, strong, watertight and resistan t to abrasion. All of these
properties are influenced by the _______ of the Portland cement paste.
a. quantity
b. weight percent
c. quality
d. density
5. The major phases in Portland cement are：_____，______，
_____ and ferrite.
a. alite
b. limestone
c. aluminate
d. belite
e. silica
f. calcium sulfate
g. ferrite
历史老照片不能说的秘密慈禧军阀明末清初文革晚清
四、Terms and definitions (4’×5 = 20’)
1. Composite
2. Fatigue limit
3. Brass
4. Physical properties
5. Worka bility
五、Questions and replies (8’×4 = 32’)
1. 指出原子键的四种类型；简述各性能特点；为各键型举例一种材料。

2. What are the differences between ceramics and glass in structure, pro perties and manufacturing
methods? Answer:
3. What are the main mechanical properties of a material investigated wi th the tensile test?
4. Please list the three reactions during the addition polymerization proc ess and explain how the
process is terminated.
六、Read and discuss (9’×2 = 18’)
1. Concrete has several unusual characteristics that make it the most ver satile and widely used of all construction materials. Freshly mixed concre te is a combination of aggregates (inert materials) and a paste composed of Portland cement and water. The aggregates generally used are sand a nd gravel or crushed stone. These aggregates have no cementing value o f their own; their function in concrete is to serve as a filler. The cement-water paste changes from a semifluid substance into a solid binder as a r esult of chemical reactions between the water and the various compoun ds in the cement. The final quality of the concrete depends upon the eff ectiveness of the hardened paste in
binding the aggregate particles together and in filling the voids between the particles.
Questions: (1) How many types of raw materials involving in concrete p roduction And what are their functions, respectively
(2) Analyze the major factors affecting concrete quality.
2. Several stress–
strain plots are shown in Figure 1. One of the lines shows the character o f fiber. Questions: Point out the polymeric materials of the other three l ines. How to classify plastics? Please give some examples for different pr operties of plastics.
Fig. 1: Stress-strain plots Strain, △L/L
Stress, (N·cm-2)
Fiber
(1) (2)
(3)
标准答案（B卷）
一、Fill in the blanks (1’×10 = 10’)
1. The advantage of microwave heating is that it is extremely rapid .
2. The mechanical properties of ceramics are good in compression , The greatest weakness is brittleness .
3. Ferrous Alloys normally contains maj or phases, called austenite, cementite, graphite, martensitic.
4. The com ponents as well as the interface between them can usually be physically i dentified.
5.
Surface treatment of reinforcing materials is done to improve the adhe sion of fillers and fibers to matrix resin by modifying the surface of the s olid.
6. The properties of materials are defined by the nature of their chemica l bonds, their atomic ordering and
their microstructure.
二、True or false (indicate with “√” or “×”, 1’×10 = 10’)
1. (×) All amorphous materials are glasses.
2. (×) Aluminum alloys offer superior specific strength in high temperat ures.
3. (√) The properties of crystals are different in various crystallogr aphic directions.
4. (√) Titanium alloys have lower density and high stre ngth.
5. (√) Most of life and industrial glass are made from silica and silicate g lasses.
6. (√) Magnesium is the lightest of all structural metals.
7. (√) Glasses is made from elements, simple chemical compounds, com plex organic molecules, salt mixtures and alloys.
8. (√) Glass when newly formed, with a perfect surface, is very strong a bout five times as strong as steel. 9. (×) MMC、PMC、
CMC are all composite, and matrix are metal, ceramic and organic polym er. 10. (√) 玻璃化温度和熔点是表征聚合物热性能的重要指标。

.
三、Choose the right answer (1’×10 = 10’)
1. Which of the following descriptions would not be applicable to cerami cs? (d)
a. Mixed ionic and covalent bonding
b. Brittle
c. Hard
d. Ductile 2 . 组成铸铁的基本元素是__________ (b, d, e)
a. O;
b. C;
c. S;
d. Si;
e. Fe;
f. Al;
g. P 3. 低合金钢合金元素含量
______，而高合金钢_________。

（b, c)
a.<2%;
b.<5%;
c. >10%;
d.>13%
4. Hardened concrete should be durable, strong, watertight and resistan t to abrasion. All of these
properties are influenced by the _______ of the Portland cement paste.
(c) a. quantity b. weight percent c. quality d. density
5. The major phases in Portland cement are：_____，______，
_____ and ferrite. (a, c, d)
a. alite
b. limestone
c. aluminate
d. belite
e. silica
f. calcium sulfate
g. ferrite
四、Terms and definitions (4’×5 = 20’)
1. Composite：
A composite is a combined materials created by the synthetic assembly of two or
more components a selected filler or reinforcing agent and a compatible matrix binder in order to obtain specific characteristics and properties.
2. Fatigue limit：
The maximum load in pounds per square inch that can be applied an infi nite
number of times without causing failure.
3. Brass: An alloy of copper and zinc.
4. Physical properties: The behavior of materials subjected to the action of temperature, electric or
magnetic fields or light.
5. Workability: The ease with which concrete is placed and consilidated.
五、Questions and replies (8’×4 = 32’)
1. Answers: ①离子键(1’)：结合力很大，离子晶体的硬度高，强度大，热膨胀系数小，脆性
大。

例：陶瓷材料(1’)。

②共价键(1’)：结合力很大，共价晶体的硬度高、强度高、脆性大、熔点高、沸点高和挥发性低。

例：陶瓷材料(1’)。

③金属键 (1’)：良好的导电性和导热性，正的电阻温度系数，不透明并呈现特有的金属光泽，良好的塑性变形能力，强韧性好。

例：金属材料(1’)。

④范特瓦尔斯力(1’)：很弱，分子键结合的固体材料熔点低、硬度也很低，无自由电子，良好的绝缘性。

例：聚合物材料(1’)。

2. Answers: 1) 结构：陶瓷：晶体材料；玻璃：非晶态。

(2’) 2) 性质：陶瓷：不透明，
耐高温，具有固定的熔点，各相异性；(2’); 玻璃：透明，不耐高温，不具有固定的熔点，各相同性。

(2’) 3) 制备方法：陶瓷：先成型，再烧结；缓慢冷却以利于晶体形成；玻璃：熔融后成型，淬冷法。

(2’).
3. Answers: they are the ductility [1’], tensile strength [1’], proportional l imit [1’], elastic limit [1’],
modulus of elasticity [1’], resilience [1’], yield point, yield strength [1’], ul timate strength and breaking strength [1’].
4. Answers: The three significant reactions that take place in addition pol ymerization are: initiation
(2’), propagation (2’) and termination (2’). Termination typically occurs i n two ways: combination and disproportionate (2’).
六、Read and discuss (9’×2 = 18’)
1. Answers:
(1) Types of raw materials：
Portland cement paste, water. sand and gravel (3’).
Functions: aggregates serve as a filler; the cement-
water paste changes from a semifluid substance into a solid binder(3’).
(2) The final quality of the concrete depends upon the effectiveness of th
e hardened paste in binding the aggregate particles together and in fillin g the voids between the particles (3’).
2. Answers：
1. i. The other lines are: (1) Rigid plastic [1’]; (2) Flexible plastic [1’]; (3) El astomer [1’]. ii. There are two types of plastics—
flexible plastics and rigid plastics [2’].
iii. Flexible plastics: possess moderate to high degrees of crystallinity a nd a wide range of Tm and Tg values. They have moderate to high tensile strengths, and ultimate elongation [2’].
iv. Rigid plastics: have high moduli and moderate to high tensile strength s, they undergo very small elongations before rupturing。