TECHNICAL FIELD

The invention, relates to a low-lead brass alloy.

STATE OF THE ART

Copper has a high electrical conductivity and is also an environmentally friendly material. In addition, harmful bacteria cannot survive on the copper surface. Other elements are added to the copper to increase its performance. For example, adding lead to a brass alloy containing copper and zinc significantly improves the cutting performance of the brass. However, high lead rate has a devastating effect on human health and ecological balance. Therefore, worldwide restrictions apply to the use of lead-containing alloys.

Usually, 38-42% metallic zinc is added for easier machining of brass. 2-3% lead is added to the brass to increase its toughness and machinability. Lead-containing brass has excellent moldability (making it easy to manufacture products of various shapes), cutting performance and wear resistance, so it is widely applied to mechanical parts of various shapes, has a large proportion in the copper industry and is known as one of the most important basic materials in the world. However, during the production or use of lead-containing brass, lead tends to dissolve in solid or gaseous state. Medical studies have shown that lead can cause significant damage to the human hematopoietic and nervous systems, especially pediatric kidneys and other organs.

Therefore, there is a need to provide an alloy formula to solve the above problems, which will be an alternative to the high lead content of brass, good fluidity and also excellent casting performance, polishability quality, cutting performance and mechanical properties.

Publication EP2963134B1 relates to a low-lead brass alloy containing: by weight of the brass alloy, 62.5-63% copper by weight, 0.16-0.24% lead by weight, 0-0.02% by weight antimony, 0-0.01% by weight magnesium, 0% by weight 0.2% tin, 0.0005% by weight boron, 0.55-0.7% by weight aluminum, 0.05-0.15% by weight iron, 0-0.15% by weight nickel, 0.09-0.12% by weight arsenic, 0-0.005% by weight zirconium, and the remaining zinc as balancer speaks of the inclusion. BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to provide a brass alloy with improved fluidity, improved castability, improved mechanical properties and polishability quality, along with new laws that require the removal of lead from the alloy to minimize the toxic effect of lead on human health.

In order to achieve the said objectives, the invention comprises 55 to 65%, by weight, of copper; 0.0001 to 0.5%, by weight, of boron; 0.01 to 0.2%, by weight, of lead; Containing 0.001 to 0.5%, by weight, of iron; 0.01 to 0.3%, by weight, of tin; It is a brass alloy containing 0.1% to 0.4%, by weight, of aluminum, 0.0001% to 0.02%, nickel and it is characterized by; It contains 35% to 45%, by weight, of zinc.

In a preferred chemical composition of the invention, it is characterized in that it contains 57 to 62%, by weight, of copper. Selecting the ratio of copper in the brass alloy among the specified values provides an advantage in terms of production efficiency, structural properties, strength, and also electrical conductivity is at acceptable levels according to the place of use, and is also preferred because it is an easily pourable material.

In a preferred chemical composition of the invention, it is characterized in that it contains 0.05 to 0.3%, by weight, of iron. In brass alloy, iron effects grain refining by combining with boron.

In a preferred chemical composition of the invention, it is characterized by containing 0.00028% to 0.0012%, by weight, of boron. In brass alloy, boron effects grain refining by combining with iron.

In a preferred chemical composition of the invention, it is characterized in that it contains from 0.05 to 0.15%, by weight, of tin. The strength and corrosion resistance of the brass alloy should be increased according to the usage areas. Therefore, by adding tin to the brass alloy, the strength and corrosion resistance of the brass are increased.

In a preferred chemical composition of the invention; It is characterized by containing 0.15 to 0.3% weight of aluminum. Brass is added to increase the castability of the alloy. However, it has an increasing effect on strength and hardness values. In a preferred chemical composition of the invention, it is characterized in that it contains 36 to 44%, by weight, of zinc. Brass alloy is formed by adding zinc to the alloy. Castability and at the stated weight % ratio has a positive effect on strength.

In a preferred chemical composition of the invention, it is characterized in that it contains 37 to 43%, by weight, of zinc. The ratio of zinc in the alloy to the castability weight ratio provides the improvement of the properties of castability, strength optimization.

In a preferred chemical composition of the invention, the ratio of boron weight ratio to ironnickel total weight ratio is 0.002 to 0.2%. Thus, boron effects in iron-nickel combinations in grain refining of the brass alloy. Fluidity increase castability. Iron can increase the toughness of the brass alloy.

In a preferred chemical composition of the invention, the ratio of boron weight ratio to ironnickel total weight ratio is 0.0025 to 0.12%.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the development of the invention is described with reference to the examples so that there is no restriction and only to better explain the subject.

As an alternative to high-lead brass, there is a need to provide an alloy formula to solve the above problems, which have reduced lead, good fluidity, and also excellent casting performance, polishability quality, cutting performance, Tatur testing and mechanical properties. Regarding the formulation, the properties of the brass alloy are explained in detail according to the element ratios selected in the ranges given in the table below.

The table lists 10 different components, each by weight. In examples 1 to 8 in the table, the alloy contains 57.34% by weight copper, 42.2% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to and 0.0006% by weight boron addition, the alloy has poor Tatur performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 9 to 16 in the table, the alloy contains 57.62%, by weight, of copper, 41.87%, by weight, of zinc, 0.1%, by weight, lead, 0.1%, by weight, of iron, 0.2%, by weight, of aluminum, 0.1%, by weight, of tin, 0.01%, by weight, of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006%, by weight, of boron addition, the alloy has poor Tatur performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 17 to 24 in the table, the alloy contains 57.74%, by weight, of copper, 41.7%, by weight of zinc, 0.1%, by weight, of lead, 0.1% by weight of iron, 0.25% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 25 to 32 in the table, the alloy contains 57.86% by weight of copper, 41.55% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.28% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying rates, the alloy has poor turtar performance and poor grain structure up to 0.0006% by weight and up to the addition of boron at higher weight ratio, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 33 to 40 in the table, the alloy contains 57.84% by weight of copper, 41.6% by weight of zinc, 0.1% by weight of lead, 0.14% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.0004% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 41 to 48 in the table, the alloy contains 58.25% by weight of copper, 41.13% by weight of zinc, 0.1% by weight of lead, 0.2% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00054 to 0.0012%. Due to these varying ratios, up to 0.00065% by weight boron addition, the alloy has poor taper performance and poor grain structure, but good fluidity and good mechanical properties. After adding boron higher than 0.00065% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 49 to 56 in the table, the alloy contains 58.59% by weight of copper, 40.74% by weight of zinc, 0.1% by weight of lead, 0.25% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00065% to 0.0012%. Due to these varying ratios, 0.00065% by weight boron addition, the alloy has poor tatur performance and bad grain structure, but good fluidity, good mechanical properties. After adding boron higher than 0.00065% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 57 to 64 in the table, the alloy contains 59.09% by weight of copper, 40.5% by weight of zinc, 0.05% by weight of lead, 0.2% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 65 to 72 in the table, the alloy contains 59.36% by weight of copper, 40.13% by weight of zinc, 0.15% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 73 to 80 in the table, the alloy contains 59.64% by weight of copper, 39.82% by weight of zinc, 0.18% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 81 to 88 in the table, the alloy contains 59.72% by weight of copper, 39.82% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 89 to 96 in the table, the alloy contains 59.36% by weight of copper, 40.13% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 97 to 104 in the table, the alloy contains 58.94% by weight of copper, 40.5% by weight of zinc, 0.18% by weight of lead, 0.1% by weight of iron, 0.25% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying rates, up to 0.0006% by weight boron addition, the alloy has poor taper performance and bad grain structure, but good fluidity, good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 105 to 112 in the table, the alloy contains 58.67% by weight of copper, 40.74% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.28% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 113 to 120 in the table, the alloy contains 58.31% by weight of copper, 41.13% by weight of zinc, 0.1% by weight of lead, 0.14% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.0004% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron higher than 0.0006% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 121 to 128 in the table, the alloy contains 57.78% by weight of copper, 41.6% by weight of zinc, 0.1% by weight of lead, 0.2% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00054 to 0.0012%. Due to these varying ratios, up to 0.00065% by weight boron addition, the alloy has poor taper performance and poor grain structure, but good fluidity and good mechanical properties. After adding boron higher than 0.00065% by weight, an alloy with good Tatur results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 129 to 136 in the table, the alloy contains 57.78% by weight of copper, 41 .55% by weight of zinc, 0.1% by weight of lead, 0.25% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.00065% to 0.0012%. Due to these varying rates, up to 0.0007% by weight boron addition, the alloy has poor taper performance and bad grain structure, but good fluidity, good mechanical properties. After adding boron higher than 0.0007% by weight, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 137 to 144 in the table, the alloy contains 57.89% by weight of copper, 41.7% by weight of zinc, 0.05% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying rates, up to 0.0006% by weight boron addition, the alloy has poor taper performance and bad grain structure, but good fluidity, good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 145 to 152 in the table, the alloy contains 57.62% by weight of copper, 41 .87% by weight of zinc, 0.15% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00054 to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 153 to 160 in the table, the alloy contains 57.26% by weight of copper, 42.8% by weight of zinc, 0.18% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 161 to 168 in the table, the alloy contains 59.74% by weight of copper, 39.8% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 169 to 176 in the table, the alloy contains 59.94% by weight of copper, 39.55% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples numbered 177 to 184 in the table, the alloy contains 60.14% by weight of copper, 39.3% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.25% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 185 to 192 in the table, the alloy contains 60.36% by weight of copper, 39.05% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.28% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 193 to 200 in the table, the alloy contains 60.64% by weight of copper, 38.8% by weight of zinc, 0.1% by weight of lead, 0.14% by weight of iron, 0.25% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.0004% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 201 to 208 in the table, the alloy contains 60.9% by weight of copper, 38.48% by weight of zinc, 0.1% by weight of lead, 0.2% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00054 to 0.0012%. Due to these varying ratios, up to 0.00065% by weight boron addition, the alloy has poor taper performance and poor grain structure, but good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 209 to 216 in the table, the alloy contains 61.15% by weight of copper, 38.18% by weight of zinc, 0.1% by weight of lead, 0.25% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00065% to 0.0012%. Due to these varying ratios, up to 0.00065% by weight boron addition, the alloy has poor taper performance and poor grain structure, but good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 217 to 224 in the table, the alloy contains 61.39% by weight of copper, 38.2% by weight of zinc, 0.05% by weight of lead, 0.11% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying rates, up to 0.0006% by weight boron addition, the alloy has poor taper performance and bad grain structure, but good fluidity, good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 225 to 232 in the table, the alloy contains 61 .69% by weight of copper, 37.8% by weight of zinc, 0.15% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 233 to 240 in the table, the alloy contains 61 .86% by weight of copper, 37.6% by weight of zinc, 0.18% by weight of lead, 0.14% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying rates, up to 0.0006% by weight boron addition, the alloy has poor taper performance and bad grain structure, but good fluidity, good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 241 to 248 in the table, the alloy contains 61 .94% by weight of copper, 37.6% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.15% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and The boron weight ratio added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 249 to 256 in the table, the alloy contains 61 .69% by weight of copper, 37.8% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 257 to 264 in the table, the alloy contains 61.24% by weight of copper, 38.2% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.25% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 265 to 272 in the table, the alloy contains 61 .23% by weight of copper, 38.18% by weight of zinc, 0.1% by weight of lead, 0.1% by weight of iron, 0.28% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 273 to 280 in the table, the alloy contains 60.96% by weight of copper, 38.48% by weight of zinc, 0.1% by weight of lead, 0.14% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.0004% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 281 to 288 in the table, the alloy contains 60.58% by weight of copper, 38.8% by weight of zinc, 0.1% by weight of lead, 0.2% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00054 to 0.0012%. Due to these varying ratios, up to 0.00065% by weight boron addition, the alloy has poor taper performance and poor grain structure, but good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In examples 289 to 296 in the table, the alloy contains 60.28% by weight of copper, 39.05% by weight of zinc, 0.1% by weight of lead, 0.25% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.015% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00065% to 0.0012%. Due to these varying ratios, up to 0.00065% by weight boron addition, the alloy has poor taper performance and poor grain structure, but good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 297 to 304 in the table, the alloy contains 60.29% by weight of copper, 39.3% by weight of zinc, 0.05% by weight of lead, 0.1% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In samples 305 to 312 in the table, the alloy contains 59.94% by weight of copper, 39.55% by weight of zinc, 0.15% by weight of lead, 0.1% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and the boron weight ratio added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.

In examples 313 to 320 in the table, the alloy contains 59.66% by weight of copper, 39.8% by weight of zinc, 0.18% by weight of lead, 0.1% by weight of iron, 0.2% by weight of aluminum, 0.1% by weight of tin, 0.01% by weight of nickel and The weight ratio of boron added to the alloy ranges from 0.00028% to 0.0012%. Due to these varying ratios, up to 0.0006% by weight boron addition, the alloy has poor taper performance and poor grain structure, but has good fluidity and good mechanical properties. After adding boron 0.0007% by weight or higher, an alloy with good Tatar results, good grain structure, good fluidity and good mechanical properties is obtained.